
The present disclosure relates to the field of
optical fiber
transmission. More particularly, the present disclosure
relates to a
low cut
-
off no
n
-
zero dispersion shifted fiber
for long haul, metro and
communication applicat
i
ons.
BACKGROUND

Over the last few years, optical fibers are bein
g widely used
for
tele
communication
s
applications
. One such type of optical fiber
is
non
-
zero dispersion shifted optical fiber used in
long haul and
metro
applications.
Typically, the performance of these optical
fibers is determined based on a
low
dispersion, cut
-
off wavelength
and bending losses over a broad range of bandwidth.
In general, the
dispersion and bending losses are minimiz
ed based on a refractive
index profile
. The refractive index profile defines the properties of a
core section and a cladding section. Also, the refractive index
profile illustrates a relationship between the refractive index of the
optical fiber with a ra
dius of the optical fiber. Further, this profile is
determined based on a concentration of dopants and materials used
during manufacturing. Furthermore, the dispersion and bending
losses are controlled by varying the refractive index profile.
Other
para
meters that affect the performance of the fibers includes
thickness of each region of the fiber and peak shaping parameter

In one of the prior arts
US 7106934 B1
,
a
non
-
z
ero
dispersion shifted optical fiber
is provided
.
The non
-
zero dispersion
3
/
38
shifted
fiber includes
a core having a centerline and a refractive
index profile and a cladding surrounding the core. The core
includes
a central region extending radially outwardly from the centerline, a
first annular region surrounding the central region, and a
second
annular region surrounding the first annular region.
The
above
stated prior art has
certain drawbacks. The non
-
zer
o dispersion
shifted fibers
of
ITU
-
T G.656
category
exhibit
s
high macro bending
losses
and high cut
-
off wavelength
values
leading to
increase in
system penalty and network budget. This leads to reduction in
reliability of optical fiber under bending conditions
for long haul and
metro applications
.

In light of the above stated discussion, there is a need for an
optical fiber
that has low macro bending losses
, low dispersion
losses and low cable cut
-
of
f
wavelength while being suitable
for
long h
aul communications.
OBJECT OF THE DISCLOSURE

A primary object of the present disclosure is to
provide an
optical fiber
with
low macro bending losses
.

Another object of the present disclosure is to provide an
optical fiber
with
low dispersion values.

Yet a
nother object of the present disclosure is to
provide an
optical fiber
with
low cut
-
off wavelength to operate in O &
E bands.
4
/
38

Yet another object of the pres
ent disclosure is to provide an
optical fibe
r which can be used for long haul, metro and
communication applications.
SUMMARY

In an aspect of the present disclosure, the present disclosure
provides a low cut
-
off,
low bend loss
no
n
-
zero and dispersion shifted
optical fiber. The
optical fiber includes a core region. A
core region
defined by a region around a central longitudinal axis of the optical
fiber. In addition, the core region has a first
annular
region.
T
he
first
annular
region is defined from the central longitudinal axis to a
first radius r
1
from the central longitudinal axis of the
optical fiber.
Moreover, the core region has a second
annular
region
.
The
second
annular region
is defined from the first radius r
1
to a second radius r
2
from the central longitudinal axis of the
optical fiber. Further, the
core has a third
annular
region. The third
annular
region is defined
from the second radius r
2
to a third radius r
3
from the
central
longitudinal axis of the
optical fiber.
The first
annular
region, the
second
annular
region and the third
annular
region are concentrically
arranged.
Also, the optical fiber includes a cladding.
The cladding
has a fourth refractive index
Δ
4
and
a fourth radius r
4
from the central
longitudinal axis of the
optical fiber
.
The
fourth annular region
concentrically surrounds the
third annular region
. In addition, the
first radius r
1
is in range of 2.75
μm
and 3.21
μm
.
Moreover
, the
first refractive index
Δ
1
is in range of 0.56 and 0.73.
Further, the
second radius r
2
is
in range of 5.2
μm
and 6.42
μm
.
Furthermore,
the
second refractive index
Δ
2
is in range of 0.04 and 0.19
.
Furthermore,
the third radius r
3
is in range of 8.26
μm
and 10.09
μm
.
Furthermore,
5
/
38
the third refractive index
Δ
3
is in range of 0.09 and 0.22.
Furthermore the fourth radius r
4
is in range of 62.15
μm
and 62.85
μm
.
Furthermore, the fourth refractive index
Δ
4
is zero.

In an embodiment of the present
disclosure, the
optical fiber
has a peak shaping alpha parameter of the central core in the range of
1.66 to 3.84.

In an embodiment of the present disclosure,
the optical fiber
has a chroma
tic dispersion in the range of 1
ps/nm.km
to 4.6
ps/nm.km
at a wav
elength of 1460 nm of the optical fiber.

In an embodiment of the present disclosure,
the optical fiber
has a chromatic dispersion in the range of 3.02
ps/nm.km
to 8.24
ps/nm.km
at a wavelength of 1530 nm of the optical fiber.

In an embodiment of the pres
ent disclosure,
the optical fiber
has a chromatic dispersion in the range of 3.6
ps/nm.km
to 9.28
ps/nm.km
at a wavelength of 1550 nm of the optical fiber.

In an embodiment of the present disclosure,
the optical fiber
has a chromatic dispersion in the range of 3.8
ps/nm.km
to 10.23
ps/nm.km
at a wavelength of 1565 nm of the optical fiber.

In an embodiment of the present disclosure,
the optical fiber
has a chromatic dispersion in the range of 4.58
ps/nm.km
to 13.8
ps/n
m.km
at a wavelength of 1625 nm of the optical fiber.
6
/
38

In an embodiment of the present disclosure,
the optical fiber
has a macrobending loss of less than 0.05 dB/1 turn,
preferably less
than 0.04 dB/1 turn, more preferably less than 0.03 dB/1 turn and
most preferably less than 0.02 dB/1 turn
for
32 mm bending
diameter
at a wavelength of 1550 nm
.

In an embodiment of the present disclosure, the optical fiber
has a
macrobending loss of less than 0.05 dB/1 turn, preferably less
than 0.04 dB/1 turn, more preferably less than 0.03 dB/1 turn and
most preferably less than 0.02 dB/1 turn
for
32 mm bending
diameter
at a wavelength of 1625 nm
.

In an embodiment of the present
disclosure,
the optical fiber
has a macrobending loss of less than 0.05 dB/100 turns
for
60 mm
bending diameter
at a wavelength of 1550 nm
.

In an embodiment of the present disclosure,
the optical fiber
has a macrobending loss of less than 0.05 dB/100 tur
ns
for
60 mm
bending diameter
at a wavelength of 1625 nm
.

In an embodiment of the present disclosure,
the cable cut
-
off wavelength of the optical fiber
is
less than
1260 nm.
STATEMENT OF DISCLOSURE

The present disclosure relates to a low cut
-
off,
low
macrobend loss
and
non
-
zero dispersion shifted optical fiber. The
optical fiber includes a core region. A core region defined by a
region around a central longitudinal axis of the optical fiber. In
7
/
38
addition, the core region has a
first annular region
.
The
first annular
region
is defined from the central longitudinal axis to a first radius r
1
from the central longitudinal axis of the optical fiber. Moreover, the
core region has a
second annular region
. The
second annular region
is defined from the firs
t radius r
1
to a second radius r
2
from the
central longitudinal axis of the optical fiber. Further, the core has a
third annular region
. The
third annular region
is defined from the
second radius r
2
to a third radius r
3
from the central longitudinal axis
of the optical fiber. The
first annular region
, the
second annular
region
and the
third annular region
are concentrically arranged.
Also, the optical fiber includes a cladding.
The cladding has a fourth
refractive index
Δ
4
and a fourth radius r
4
from t
he central
longitudinal axis of the optical fiber. The
fourth annular region
concentrically surrounds the
third annular region
. In addition, the
first radius r
1
is in range of 2.75 μm and 3.21 μm.
Moreover, the
first refractive index
Δ
1
is in range of 0.56
and 0.73. Further, the
second radius r
2
is in range of 5.20
μm
and 6.42
μm
. Furthermore,
the second refractive index
Δ
2
is in range of 0.04 and 0.19.
Furthermore, the third radius r
3
is in range of 8.26
μm
and 10.09
μm
.
Furthermore,
the third refractive index
Δ
3
is in range of 0.09 and
0.22.
Furthermore
,
the fourth radius r
4
is in range of 62.15
μm
and
62.85
μm.
Furthermore, the fourth refractive index
Δ
4
is zero.
BRIEF DESCRIPTION OF FIGURES

Having thus described the disclosure
in general terms,
reference will now be made to the accompanying figures, wherein:
8
/
38

FIG. 1
A
illustrates a cross
-
sectional view of an opti
cal
fiber, in accordance with various
embodiment
s
of the present
disclosure;

FIG. 1B
illu
strates a perspective view of
the
optical fiber
of
FIG. 1A
, in accordance with various embodiment
s of the present
disclosure;
and

FIG. 2
illustrates a refractive index profile of the opti
cal
fiber, in accordance with
an
embodiment of the present disclosure
.

It should be noted that
the accompanying figures are
intended to present illustrations of exemplary embodiments of the
present disclosure. These figures are not intended to limit the scope
of the present disclosure. It should also be noted that accompanying
figures are not nece
ssarily drawn to scale.
DETAILED DESCRIPTION

In the following description, for purposes of explanation,
numerous specific details are set forth in order to provide a thorough
understanding of the present technology. It will be apparent,
however, to one skilled in the art that the present technology
can be
practiced without these specific details. In other instances, structures
9
/
38
and devices are shown in block diagram form only in order to avoid
obscuring the present technology.

Reference in this specification to “one embodiment” or “an
embodiment” me
ans that a particular feature, structure, or
characteristic described in connection with the embodiment is
included in at least one embodiment of the present technology. The
appearance of the phrase “in one embodiment” in various places in
the specificati
on are not necessarily all referring to the same
embodiment, nor are separate or alternative embodiments mutually
exclusive of other embodiments. Moreover, various features are
described which may be exhibited by some embodiments and not by
others. Simil
arly, various requirements are described which may be
requirements for some embodiments but not other embodiments.

Moreover, although the following description contains
many specific
ation
s for the purposes of illustration, anyone skilled in
the art will a
ppreciate that many variations and/or alterations to said
details are within the scope of the present technology. Similarly,
although many of the features of the present technology are
described in terms of each other, or in conjunction with each other,
o
ne skilled in the art will appreciate that many of these features can
be provided independently of other features. Accordingly, this
description of the present technology is set forth without any loss of
generality to, and without imposing limitations upo
n, the present
technology.

FIG. 1
A
illustrates a cross
-
sectional view of an optical fiber
100
, in accordance with various embodi
ments of the present
10
/
38
disclosure and
FIG1B
illustrates a perspective view of an optical
fiber
100
, in accordance with various
embodiments of the present
disclosure.
The optical fiber
100
is a fiber
used for transmitting
information as light pulses from one end to another. In addition, the
optical fiber
100
is a thin strand of glass or plastic capable of
transmitting optical sig
nals. The optical fiber
100
is configured to
transmit large amounts of information over long distances with
relatively low attenuation. Moreover, in an embodiment of the
present disclosure, the optical fiber
100
is utilized for broadband
communication ap
plications.

In another embodiment of the present disclosure, the optical
fiber
100
may be utilized for other applications. Going further, the
optical fiber
100
is a non
-
zero dispersion shifted fiber. The non
-
zero
dispersion shifted fiber
is a single mode optical fiber used for long
haul transmission systems. The single mode optical fiber
100
is a
fiber which is configured for transmission of single mode of light. In
addition, the non
-
zero dispersion shifted fiber is a fiber used for
red
ucing dispersion in broadband communications.
The dispersion
corresponds to the
spreading of the optical signals over time.

In an embodiment of the present disclosure, the type of the
dispersion which occurs inside the single mode optical fiber
is
chromatic dispersion. The chromatic dispersion is the spreading of
the optical signals which results from different speeds of light rays
travelling inside the optical fiber
100
. Moreover, the chromatic
dispersion occurs due to material dispersion and
waveguide
dispersion.
11
/
38

The material dispersion occurs due to a change in a
refractive index of the
material
with an optical frequency. Moreover,
the waveguide dispersion occurs due to dependency of
mode
propagation on wavelength
.
Further
, the
chromatic dispersion
exhibited
by the present fiber
is less than the chromatic dispersion of
a standard single mode optical fiber
.
In an embodiment of the
present disclosure, the non
-
zero dispersion shifted fiber enables
decrease of the dispersion over a
range of wavelength and decreases
non
-
linearity in the optical fiber
100
. The range of wavelength
corresponds to a range in which the optical fiber
100
is configured to
operate.

I
n an embodiment of the present disclosure, the chromatic
dispersion
values of the optical
fiber
100
are in the range of 1
ps/nm.km
to 4.6
ps/nm.km
at
1460 nm wavelength. In another
embodiment of the present disclosure, the chromatic dispersion
values of the
optical
fiber
100
are
in the range of 3.02
ps/nm.km
to
8.24
ps/nm.km
at
1530 nm wavelength. In yet another embodiment
of the present disclosure, the chromatic dispersion
values of the
optical
fiber
100
are
in the range of 3.6
ps/nm.km
to 9.28
ps/nm.km
at
1550 nm wavelength. In yet another embodiment of the presen
t
disclosure, the chromatic dispersion values of the
optical
fiber
100
are in the range of 3.8
ps/nm.km
to 10.23
ps/nm.km
at
1565 nm
wavelength. In yet another embodiment of the present disclosure,
the chromatic dispersion
values of the optical
fiber
100
are in the
range of 4.58
ps/nm.km
to 13.8
ps/nm.km
at
1625 nm wavelength.

In an embodiment of the present disclosure, the non
-
zero
dispersion shifted fiber is a positive non
-
zero dispersion shifted
fiber. The positive non
-
zero dispersion shifted fiber
exhibits a
12
/
38
positive chromatic dispersion at the operational wavelength. In an
embodiment of the present disclosure, the optical fiber
100
complies
with specific telecommunication standards. The telecommunication
standards are defined by International Tel
ecommunication Union
-
Telecommunication (hereinafter “ITU
-
T”). In an embodiment of the
present disclosure, the optical fiber
100
is compliant with G.656
recommendation standard set by the ITU
-
T.

Furthermore, the ITU
-
T G.656 recommendation describes a
geometrical, mechanical and transmission attributes of the single
mode optical fiber (the optical fiber
100
). In an embodiment of the
present disclosure, the range of wavelength for the optical fiber
100
as per the ITU
-
T G.656 standard is 1460 nanometer to 1625
nanometer. Moreover, the ITU
-
T G.656 standard defines a plurality
of attributes associated with the optical fiber
100
. The plurality of
attributes includes a mode field diameter, a cladding d
iameter, cable
cut
-
off wavelength, macro bending loss, dispersion and refractive
index. In addition, the plurality of attributes includes core
concentricity error, cladding non
-
circularity, attenuation coefficient
and the like.

In another embodiment of t
he present disclosure, the low
cut
-
off
non
-
zero dispersion shifted optical fiber
100
exhibits low
bending losses. The bending losses correspond
to the losses that the
optical fiber
100
exhibits when they are bent. The bending loss
mainly includes macro b
ending lo
sses and micro bending losses.

In an embodiment of the present disclosure, the optical fiber
has a macrobending loss of less than 0.05 dB/1 turn, preferably less
than 0.04 dB/1 turn, more preferably less than 0.03 dB/1 turn and
13
/
38
most preferably le
ss than 0.02 dB/1 turn
for
32 mm bending
diameter
at a wavelength of 1550 nm
.
In another embodiment of the
present disclosure, the optical fiber has a macrobending loss of less
than 0.05 dB/1 turn, preferably less than 0.04 dB/1 turn, more
preferably less
than 0.03 dB/1 turn and most preferably less than
0.02 dB/1 turn
for
32 mm bending diameter
at a wavelength of 1625
nm
.
In
yet
another embodiment of the present disclosure, the optical
fiber has a macrobending
loss of less than 0.05 dB/100 turns,
preferably less than 0.04 dB/100 turns, more preferably less than
0.03 dB/100 turns and most preferably less than 0.02 dB/100 turns
for
60 mm bending diameter
at a wavelength of 1550 nm
. In yet
another embodiment of t
he present disclosure, the optical fiber has a
macrobending loss of less than 0.05 dB/100 turns, preferably less
than 0.04 dB/100 turns, more preferably less than 0.03 dB/100 turns
and most preferably less than 0.02 dB/100 turns
for
60 mm bending
diameter
at a wavelength of 1625 nm
.

In an embodiment of the present disclosure, the peak
shaping parameter
alpha of the central core region of the optical fiber
100
is optimized. In another embodiment of the present disclosure,
the optical fiber
100
has a peak s
haping alpha parameter of the
central core in the range of 1.66 to 3.84.

Going further, the optical fiber
100
includes a core region
102
and a cladding region
104
. The core region
102
is an inner part
of the optical fiber
100
and the cladding region
104
is an outer part
of the optical fiber
100
. Moreover, the core region
102
is defined by
a region around a central longitudinal axis
112
(as shown in Fig. 1B)
of the optical fiber
100
. In addition, the cladding region
104
surrounds the core region
102
. T
he core region
102
and the cladding

Claims:What is claimed is:
1. An optical fiber (100) comprising:

a core region (102) defined by a region around a central longitudinal axis (112), the core region (102) comprising:

a first annular region (106) defined from the central longitudinal axis (112) of the optical fiber (100) to a first radius r1, wherein the first annular region (106) is characterized by a first refractive index ?1, wherein the first radius r1 is in range of about 2.75 µm and 3.21 µm and the first refractive index ?1 is in range of about 0.56 and 0.73;

a second annular region (108) defined from the first radius r1 to a second radius r2 from the central longitudinal axis (112) of the optical fiber (100), wherein the second annular region (108) is characterized by a second refractive index ?2, wherein the second radius r2 is in range of about 5.2 µm and 6.42 µm and said second refractive index ?2 is in range of about 0.04 and 0.19;

a third annular region (110) defined from the second radius r2 to a third radius r3 from the central longitudinal axis (112) of the optical fiber (100), wherein the third annular region (110) is characterized by a third refractive index ?3, wherein the third radius r3 is in range of about 8.26 µm and 10.09 µm and the third refractive index ?3 is in range of about 0.09 and 0.22, wherein the first annular region (106), the second annular region (108) and the third annular region (110) are concentrically arranged; and

a cladding (104) having a fourth refractive index ?4 and fourth radius r4 from the central longitudinal axis (112) of the optical fiber (100), the cladding (104) is defined by a fourth annular region (104) concentrically surrounding the third annular region (110)., wherein the fourth radius r4 is in range of about 62.15 µm and 62.85 µm and the fourth refractive index ?4 is zero.

2. The optical fiber (100) as recited in claim 1, wherein the central core region of the optical fiber (100) has a peak shaping alpha parameter in the range of about 1.66 to 3.84.

3. The optical fiber (100) as recited in claim 1, wherein the optical fiber (100) has a chromatic dispersion in the range of about 1 ps/nm.km to 4.6 ps/nm.km at a wavelength of 1460 nm.

4. The optical fiber (100) as recited in claim 1, wherein the optical fiber (100) has a chromatic dispersion in the range of about 3.02 ps/nm.km to 8.24 ps/nm.km at a wavelength of 1530 nm.

5. The optical fiber (100) as recited in claim 1, wherein the optical fiber (100) has a chromatic dispersion in the range of about 3.6 ps/nm.km to 9.28 ps/nm.km at a wavelength of 1550 nm.

6. The optical fiber (100) as recited in claim 1, wherein the optical fiber (100) has a chromatic dispersion in the range of about 3.8 ps/nm.km to 10.23 ps/nm.km at a wavelength of 1565 nm.

7. The optical fiber (100) as recited in claim 1, wherein the optical fiber (100) has a chromatic dispersion in the range of about 4.58 ps/nm.km to 13.8 ps/nm.km at a wavelength of 1625 nm.

8. The optical fiber (100) as recited in claim 1, wherein the optical fiber (100) has a macrobending loss of less than 0.05 dB/1 turn, preferably less than 0.04 dB/1 turn, more preferably less than 0.03 dB/1 turn and most preferably less than 0.02 dB/1 turn for 32 mm bending diameter at a wavelength of 1550 nm.

9. The optical fiber (100) as recited in claim 1, wherein the optical fiber (100) has a macrobending loss of less than 0.05 dB/1 turn, preferably less than 0.04 dB/1 turn, more preferably less than 0.03 dB/1 turn and most preferably less than 0.02 dB/1 turn for 32 mm bending diameter at a wavelength of 1625 nm.

10. The optical fiber (100) as recited in claim 1, wherein the optical fiber (100) has a macrobending loss of less than 0.05 dB/100 turns for 60 mm bending diameter at a wavelength of 1550 nm.

11. The optical fiber (100) as recited in claim 1, wherein the optical fiber (100) has a macrobending loss of less than 0.05 dB/100 turns for 60 mm bending diameter at a wavelength of 1625 nm.

12. The optical fiber (100) as claimed in claim 1, wherein the optical fiber (100) has a cable cut-off wavelength of less than 1260 nm.
, Description:TECHNICAL FIELD

The present disclosure relates to the field of optical fiber transmission. More particularly, the present disclosure relates to a low cut-off non-zero dispersion shifted fiber for long haul, metro and communication applications.

BACKGROUND
Over the last few years, optical fibers are being widely used for telecommunications applications. One such type of optical fiber is non-zero dispersion shifted optical fiber used in long haul and metro applications. Typically, the performance of these optical fibers is determined based on a low dispersion, cut-off wavelength and bending losses over a broad range of bandwidth. In general, the dispersion and bending losses are minimized based on a refractive index profile. The refractive index profile defines the properties of a core section and a cladding section. Also, the refractive index profile illustrates a relationship between the refractive index of the optical fiber with a radius of the optical fiber. Further, this profile is determined based on a concentration of dopants and materials used during manufacturing. Furthermore, the dispersion and bending losses are controlled by varying the refractive index profile. Other parameters that affect the performance of the fibers includes thickness of each region of the fiber and peak shaping parameter

In one of the prior arts US 7106934 B1, a non-zero dispersion shifted optical fiber is provided. The non-zero dispersion shifted fiber includes a core having a centerline and a refractive index profile and a cladding surrounding the core. The core includes a central region extending radially outwardly from the centerline, a first annular region surrounding the central region, and a second annular region surrounding the first annular region. The above stated prior art has certain drawbacks. The non-zero dispersion shifted fibers of ITU-T G.656 category exhibits high macro bending losses and high cut-off wavelength values leading to increase in system penalty and network budget. This leads to reduction in reliability of optical fiber under bending conditions for long haul and metro applications.

In light of the above stated discussion, there is a need for an optical fiber that has low macro bending losses, low dispersion losses and low cable cut-off wavelength while being suitable for long haul communications.

OBJECT OF THE DISCLOSURE
A primary object of the present disclosure is to provide an optical fiber with low macro bending losses.

Another object of the present disclosure is to provide an optical fiber with low dispersion values.

Yet another object of the present disclosure is to provide an optical fiber with low cut-off wavelength to operate in O & E bands.

Yet another object of the present disclosure is to provide an optical fiber which can be used for long haul, metro and communication applications.

SUMMARY

In an aspect of the present disclosure, the present disclosure provides a low cut-off, low bend loss non-zero and dispersion shifted optical fiber. The optical fiber includes a core region. A core region defined by a region around a central longitudinal axis of the optical fiber. In addition, the core region has a first annular region. The first annular region is defined from the central longitudinal axis to a first radius r1 from the central longitudinal axis of the optical fiber. Moreover, the core region has a second annular region. The second annular region is defined from the first radius r1 to a second radius r2 from the central longitudinal axis of the optical fiber. Further, the core has a third annular region. The third annular region is defined from the second radius r2 to a third radius r3 from the central longitudinal axis of the optical fiber. The first annular region, the second annular region and the third annular region are concentrically arranged. Also, the optical fiber includes a cladding. The cladding has a fourth refractive index ?4 and a fourth radius r4 from the central longitudinal axis of the optical fiber. The fourth annular region concentrically surrounds the third annular region. In addition, the first radius r1 is in range of 2.75 µm and 3.21 µm. Moreover, the first refractive index ?1 is in range of 0.56 and 0.73. Further, the second radius r2 is in range of 5.2 µm and 6.42 µm. Furthermore, the second refractive index ?2 is in range of 0.04 and 0.19. Furthermore, the third radius r3 is in range of 8.26 µm and 10.09µm. Furthermore, the third refractive index ?3 is in range of 0.09 and 0.22. Furthermore the fourth radius r4 is in range of 62.15 µm and 62.85 µm. Furthermore, the fourth refractive index ? 4 is zero.

In an embodiment of the present disclosure, the optical fiber has a peak shaping alpha parameter of the central core in the range of 1.66 to 3.84.

In an embodiment of the present disclosure, the optical fiber has a chromatic dispersion in the range of 1 ps/nm.km to 4.6 ps/nm.km at a wavelength of 1460 nm of the optical fiber.

In an embodiment of the present disclosure, the optical fiber has a chromatic dispersion in the range of 3.02 ps/nm.km to 8.24 ps/nm.km at a wavelength of 1530 nm of the optical fiber.

In an embodiment of the present disclosure, the optical fiber has a chromatic dispersion in the range of 3.6 ps/nm.km to 9.28 ps/nm.km at a wavelength of 1550 nm of the optical fiber.

In an embodiment of the present disclosure, the optical fiber has a chromatic dispersion in the range of 3.8 ps/nm.km to 10.23 ps/nm.km at a wavelength of 1565 nm of the optical fiber.

In an embodiment of the present disclosure, the optical fiber has a chromatic dispersion in the range of 4.58 ps/nm.km to 13.8 ps/nm.km at a wavelength of 1625 nm of the optical fiber.

In an embodiment of the present disclosure, the optical fiber has a macrobending loss of less than 0.05 dB/1 turn, preferably less than 0.04 dB/1 turn, more preferably less than 0.03 dB/1 turn and most preferably less than 0.02 dB/1 turn for 32 mm bending diameter at a wavelength of 1550 nm.

In an embodiment of the present disclosure, the optical fiber has a macrobending loss of less than 0.05 dB/1 turn, preferably less than 0.04 dB/1 turn, more preferably less than 0.03 dB/1 turn and most preferably less than 0.02 dB/1 turn for 32 mm bending diameter at a wavelength of 1625 nm.
In an embodiment of the present disclosure, the optical fiber has a macrobending loss of less than 0.05 dB/100 turns for 60 mm bending diameter at a wavelength of 1550 nm.

In an embodiment of the present disclosure, the optical fiber has a macrobending loss of less than 0.05 dB/100 turns for 60 mm bending diameter at a wavelength of 1625 nm.

In an embodiment of the present disclosure, the cable cut-off wavelength of the optical fiber is less than 1260 nm.

STATEMENT OF DISCLOSURE

The present disclosure relates to a low cut-off, low macrobend loss and non-zero dispersion shifted optical fiber. The optical fiber includes a core region. A core region defined by a region around a central longitudinal axis of the optical fiber. In addition, the core region has a first annular region. The first annular region is defined from the central longitudinal axis to a first radius r1 from the central longitudinal axis of the optical fiber. Moreover, the core region has a second annular region. The second annular region is defined from the first radius r1 to a second radius r2 from the central longitudinal axis of the optical fiber. Further, the core has a third annular region. The third annular region is defined from the second radius r2 to a third radius r3 from the central longitudinal axis of the optical fiber. The first annular region, the second annular region and the third annular region are concentrically arranged. Also, the optical fiber includes a cladding. The cladding has a fourth refractive index ?4 and a fourth radius r4 from the central longitudinal axis of the optical fiber. The fourth annular region concentrically surrounds the third annular region. In addition, the first radius r1 is in range of 2.75 µm and 3.21 µm. Moreover, the first refractive index ?1 is in range of 0.56 and 0.73. Further, the second radius r2 is in range of 5.20 µm and 6.42 µm. Furthermore, the second refractive index ?2 is in range of 0.04 and 0.19. Furthermore, the third radius r3 is in range of 8.26 µm and 10.09 µm. Furthermore, the third refractive index ?3 is in range of 0.09 and 0.22. Furthermore, the fourth radius r4 is in range of 62.15 µm and 62.85 µm. Furthermore, the fourth refractive index ?4 is zero.

BRIEF DESCRIPTION OF FIGURES
Having thus described the disclosure in general terms, reference will now be made to the accompanying figures, wherein:

FIG. 1A illustrates a cross-sectional view of an optical fiber, in accordance with various embodiments of the present disclosure;

FIG. 1B illustrates a perspective view of the optical fiber of FIG. 1A, in accordance with various embodiments of the present disclosure; and

FIG. 2 illustrates a refractive index profile of the optical fiber, in accordance with an embodiment of the present disclosure.

It should be noted that the accompanying figures are intended to present illustrations of exemplary embodiments of the present disclosure. These figures are not intended to limit the scope of the present disclosure. It should also be noted that accompanying figures are not necessarily drawn to scale.

DETAILED DESCRIPTION

In the following description, for purposes of explanation, numerous specific details are set forth in order to provide a thorough understanding of the present technology. It will be apparent, however, to one skilled in the art that the present technology can be practiced without these specific details. In other instances, structures and devices are shown in block diagram form only in order to avoid obscuring the present technology.

Reference in this specification to “one embodiment” or “an embodiment” means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the present technology. The appearance of the phrase “in one embodiment” in various places in the specification are not necessarily all referring to the same embodiment, nor are separate or alternative embodiments mutually exclusive of other embodiments. Moreover, various features are described which may be exhibited by some embodiments and not by others. Similarly, various requirements are described which may be requirements for some embodiments but not other embodiments.

Moreover, although the following description contains many specifications for the purposes of illustration, anyone skilled in the art will appreciate that many variations and/or alterations to said details are within the scope of the present technology. Similarly, although many of the features of the present technology are described in terms of each other, or in conjunction with each other, one skilled in the art will appreciate that many of these features can be provided independently of other features. Accordingly, this description of the present technology is set forth without any loss of generality to, and without imposing limitations upon, the present technology.
FIG. 1A illustrates a cross-sectional view of an optical fiber 100, in accordance with various embodiments of the present disclosure and FIG1B illustrates a perspective view of an optical fiber 100, in accordance with various embodiments of the present disclosure. The optical fiber 100 is a fiber used for transmitting information as light pulses from one end to another. In addition, the optical fiber 100 is a thin strand of glass or plastic capable of transmitting optical signals. The optical fiber 100 is configured to transmit large amounts of information over long distances with relatively low attenuation. Moreover, in an embodiment of the present disclosure, the optical fiber 100 is utilized for broadband communication applications.

In another embodiment of the present disclosure, the optical fiber 100 may be utilized for other applications. Going further, the optical fiber 100 is a non-zero dispersion shifted fiber. The non-zero dispersion shifted fiber is a single mode optical fiber used for long haul transmission systems. The single mode optical fiber 100 is a fiber which is configured for transmission of single mode of light. In addition, the non-zero dispersion shifted fiber is a fiber used for reducing dispersion in broadband communications. The dispersion corresponds to the spreading of the optical signals over time.

In an embodiment of the present disclosure, the type of the dispersion which occurs inside the single mode optical fiber is chromatic dispersion. The chromatic dispersion is the spreading of the optical signals which results from different speeds of light rays travelling inside the optical fiber 100. Moreover, the chromatic dispersion occurs due to material dispersion and waveguide dispersion.

The material dispersion occurs due to a change in a refractive index of the material with an optical frequency. Moreover, the waveguide dispersion occurs due to dependency of mode propagation on wavelength. Further, the chromatic dispersion exhibited by the present fiber is less than the chromatic dispersion of a standard single mode optical fiber. In an embodiment of the present disclosure, the non-zero dispersion shifted fiber enables decrease of the dispersion over a range of wavelength and decreases non-linearity in the optical fiber 100. The range of wavelength corresponds to a range in which the optical fiber 100 is configured to operate.

In an embodiment of the present disclosure, the chromatic dispersion values of the optical fiber 100 are in the range of 1 ps/nm.km to 4.6 ps/nm.km at 1460 nm wavelength. In another embodiment of the present disclosure, the chromatic dispersion values of the optical fiber 100 are in the range of 3.02 ps/nm.km to 8.24 ps/nm.km at 1530 nm wavelength. In yet another embodiment of the present disclosure, the chromatic dispersion values of the optical fiber 100 are in the range of 3.6 ps/nm.km to 9.28 ps/nm.km at 1550 nm wavelength. In yet another embodiment of the present disclosure, the chromatic dispersion values of the optical fiber 100 are in the range of 3.8 ps/nm.km to 10.23 ps/nm.km at 1565 nm wavelength. In yet another embodiment of the present disclosure, the chromatic dispersion values of the optical fiber 100 are in the range of 4.58 ps/nm.km to 13.8 ps/nm.km at 1625 nm wavelength.

In an embodiment of the present disclosure, the non-zero dispersion shifted fiber is a positive non-zero dispersion shifted fiber. The positive non-zero dispersion shifted fiber exhibits a positive chromatic dispersion at the operational wavelength. In an embodiment of the present disclosure, the optical fiber 100 complies with specific telecommunication standards. The telecommunication standards are defined by International Telecommunication Union-Telecommunication (hereinafter “ITU-T”). In an embodiment of the present disclosure, the optical fiber 100 is compliant with G.656 recommendation standard set by the ITU-T.

Furthermore, the ITU-T G.656 recommendation describes a geometrical, mechanical and transmission attributes of the single mode optical fiber (the optical fiber 100). In an embodiment of the present disclosure, the range of wavelength for the optical fiber 100 as per the ITU-T G.656 standard is 1460 nanometer to 1625 nanometer. Moreover, the ITU-T G.656 standard defines a plurality of attributes associated with the optical fiber 100. The plurality of attributes includes a mode field diameter, a cladding diameter, cable cut-off wavelength, macro bending loss, dispersion and refractive index. In addition, the plurality of attributes includes core concentricity error, cladding non-circularity, attenuation coefficient and the like.

In another embodiment of the present disclosure, the low cut-off non-zero dispersion shifted optical fiber 100 exhibits low bending losses. The bending losses correspond to the losses that the optical fiber 100 exhibits when they are bent. The bending loss mainly includes macro bending losses and micro bending losses.

In an embodiment of the present disclosure, the optical fiber has a macrobending loss of less than 0.05 dB/1 turn, preferably less than 0.04 dB/1 turn, more preferably less than 0.03 dB/1 turn and most preferably less than 0.02 dB/1 turn for 32 mm bending diameter at a wavelength of 1550 nm. In another embodiment of the present disclosure, the optical fiber has a macrobending loss of less than 0.05 dB/1 turn, preferably less than 0.04 dB/1 turn, more preferably less than 0.03 dB/1 turn and most preferably less than 0.02 dB/1 turn for 32 mm bending diameter at a wavelength of 1625 nm. In yet another embodiment of the present disclosure, the optical fiber has a macrobending loss of less than 0.05 dB/100 turns, preferably less than 0.04 dB/100 turns, more preferably less than 0.03 dB/100 turns and most preferably less than 0.02 dB/100 turns for 60 mm bending diameter at a wavelength of 1550 nm. In yet another embodiment of the present disclosure, the optical fiber has a macrobending loss of less than 0.05 dB/100 turns, preferably less than 0.04 dB/100 turns, more preferably less than 0.03 dB/100 turns and most preferably less than 0.02 dB/100 turns for 60 mm bending diameter at a wavelength of 1625 nm.

In an embodiment of the present disclosure, the peak shaping parameter alpha of the central core region of the optical fiber 100 is optimized. In another embodiment of the present disclosure, the optical fiber 100 has a peak shaping alpha parameter of the central core in the range of 1.66 to 3.84.

Going further, the optical fiber 100 includes a core region 102 and a cladding region 104. The core region 102 is an inner part of the optical fiber 100 and the cladding region 104 is an outer part of the optical fiber 100. Moreover, the core region 102 is defined by a region around a central longitudinal axis 112 (as shown in Fig. 1B) of the optical fiber 100. In addition, the cladding region 104 surrounds the core region 102. The core region 102 and the cladding region 104 are formed along the central longitudinal axis 112 of the optical fiber 100. Moreover, the core region 102 and the cladding region 104 are formed during the manufacturing stage of the optical fiber 100.

In an embodiment of the present disclosure, the core region 102 includes a first annular region 106, a second annular region 108 and a third annular region 110. The first annular region 106 is defined from the central longitudinal axis 112 to a first radius r1 from the central longitudinal axis 112 of the optical fiber 100. The first annular region 106 has a first refractive index ?1. The second annular region 108 is defined from the first radius r1 to a second radius r2 from the central longitudinal axis 112 of the optical fiber 100. The second annular region 108 has a second refractive index ?2. The third annular region 110 is defined from the second radius r2 to a third radius r3 from the central longitudinal axis 112 of the optical fiber 100. The third annular region 110 has a third refractive index ?3. The fourth annular region (cladding region) 104 is defined from the third radius r3 to a fourth radius r4 from the central longitudinal axis 112 of the optical fiber 100. The fourth annular region 104 has a fourth refractive index ?4. The cladding 104 surrounds the core region 102. In addition, the cladding 104 is concentrically arranged around the core region 102. Moreover, the cladding 104 covers the core region 102. In an embodiment of the present disclosure, the refractive index ?4 and the radius r4 of the cladding 104 is optimized for achieving the pre-defined value of the dispersion and the macro bending loss in the optical fiber 100.

The second annular region 108 surrounds the first annular region 106, the third annular region 110 surrounds the second annular region 108 and the fourth annular region 104 surrounds the third annular region 110. Further, the first annular region 106, the second annular region 108, the third annular region 110 and the fourth annular region 104 is associated with the corresponding refractive index and the corresponding radius.

In an embodiment of the present disclosure, the refractive index of the first annular region 106, the second annular region 108, the third annular region 110 and the fourth annular region 104 is optimized for low macro bending loss, low cable cut-off and low dispersion. In another embodiment of the present disclosure, the refractive index of the cladding region 104 is throughout constant. Moreover, the macro bending loss and the dispersion is optimized within a pre-defined limit specified by the ITU-T. In an embodiment of the present disclosure, the refractive index and the radius are optimized based on a change in the concentration of a dopant used. In an embodiment of the present disclosure, the dopant includes germanium dioxide, phosphorous pentoxide, aluminium trioxide and the like.

The refractive index profile determines a relationship between the refractive index of the optical fiber 100 with a radius of the optical fiber 100. In addition, the refractive index profile illustrates a change in the refractive index of the optical fiber 100 with an increase in the radius of the optical fiber100. Further, the refractive index profile is maintained as per a desired level based on a concentration of chemicals used for the production of the optical fiber 100. In an embodiment of the present disclosure, the first radius r1 is in the range of 2.75 µm and 3.21 µm and the first refractive index ?1 is in range of 0.56 and 0.73. In another embodiment of the present disclosure, the second radius r2 is in range of 5.2 µm and 6.42 µm and the second refractive index ?2 is in range of 0.04 and 0.19. In yet another embodiment of the present disclosure, the third radius r3 is in range of 8.26 µm and 10.09 µm and the third refractive index ?3 is in range of 0.09 and 0.22. Further, the first annular region 106, the second annular region 108 and the third annular region 110 are concentrically arranged.

In an embodiment of the present disclosure, the production of the optical fiber 100 is carried out after construction of an optical fiber preform. Moreover, the refractive index profile of the optical fiber 100 is determined during the manufacturing of the optical fiber preform. The refractive index profile is determined based on a concentration of chemicals used during the manufacturing of the optical fiber preform. The chemicals used for the manufacturing of the optical fiber 100 include one or more materials and one or more dopants. Moreover, the one or more materials and the one or more dopants are deposited over a surface of an initial material by performing flame hydrolysis. In an embodiment of the present disclosure, the initial material is a substrate rod or a tube. The deposition is done for achieving a pre-structure of the optical fiber 100.

Further, the one or more materials correspond to a mixture of chemicals used for forming the optical fiber 100. The one or more materials include silicon dioxide. The silicon dioxide is deposited over the initial material during the manufacturing of the optical fiber 100. Also, silicon dioxide is formed by using a precursor material. The precursor material corresponds to silicon tetrachloride. In an embodiment of the present disclosure, the one or more dopants include germanium dioxide, phosphorous pentoxide, aluminium trioxide and the like. Moreover, germanium dioxide is formed by using a precursor material. The precursor material corresponds to germanium tetrachloride. In addition, each of the one or more dopants in added in a pre-determined quantity based on a specific requirement. Moreover, the one or more dopants are added for defining the refractive index profile of the core region of the optical fiber 100.

In an embodiment of the present disclosure, the radius of the optical fiber 100 is maintained under a pre-defined value set as per the ITU-T standards. In addition, the optical signals to be transmitted travel through the core region of the optical fiber 100. The optical signals are confined inside the core region 102 based on a property of total internal reflection. In an embodiment of the present disclosure, the core region 102 is associated with a different refractive index profile.

In an embodiment of the present disclosure, the cladding region 104 is defined by a different refractive index profile. Moreover, the refractive index profile of the core region 102 and the cladding region 104 is shown through a single graph (as shown in the FIG. 2). Going further, the optical fiber 100 includes the core region 102. The core region 102 has the refractive index profile (as shown in the FIG. 2). In addition, the optical fiber 100 includes a plurality of regions in the core region 102 of the optical fiber 100. In an embodiment of the present disclosure, the core region 102 of the optical fiber 100 is divided into the plurality of regions.

Each of the plurality of regions is defined by a corresponding refractive index and a corresponding radius. In an embodiment of the present disclosure, the refractive index of each of the plurality of regions of the core region 102 is different. In an embodiment of the present disclosure, the radius of each of the plurality of regions of the core region 102 is different. In an embodiment of the present disclosure, the refractive index of each of the plurality of regions of the core region 102 changes gradually and smoothly.

In an embodiment of the present disclosure, the equation used for calculating the refractive index (? % value) is

?%=100 (n_imax^2-n_c^2)/(2(n_imax^2))

wherein, ? is the refractive index of the region with respect to cladding
nimax is the maximum refractive index of the corresponding region.
nc is the refractive index of the undoped silica.

In an embodiment of the present disclosure, the equation use to calculate the refractive index value of central core is
n(r)=n_max (1-2??(r/r1)?^a )^(1/2), where r = r1

Wherein, r is the radius of the optical fiber,
? is the refractive index of the region with respect to cladding.
n(r) is the varying refractive index with respect to the radius of the optical fiber.
r1 is the radius of core.
a is the peak shaping parameter.
nmax is the maximum refractive index of the first annular region.

In an embodiment of the present disclosure, the mode field diameter of the optical fiber 100 is determined. The mode field diameter (MFD) is an expression of distribution of the optical power. It is measured using Peterman II method where MFD = v2 [(?¦?E^2 (r)dr?)/(?¦?[(dE(r))/dr]^2 rdr?)]^(1/2)
The integral limits being 0 to infinity. In another embodiment of the present disclosure, mode field diameter plays an important role in estimating macro bending losses.

In an embodiment of the present disclosure, the attenuation values at different wavelengths in the optical fiber 100 are determined. Attenuation is defined as the reduction in power of the light signal as it is transmitted. Attenuation is majorly caused due to rayleigh scattering and material absorption.

In an embodiment of the present disclosure, the Zero Dispersion wavelength of the optical fiber 100 is determined. The zero-dispersion wavelength is the wavelength or wavelengths at which material dispersion and waveguide dispersion cancel one another.

In an embodiment of the present disclosure, the radius r1 of the first annular region 106 is 2.9 µm, the radius r2 of the second annular region 108 is 6.42 µm and the radius r3 of the third annular region 110 is 9.63 µm. The cable cut-off wavelength of the optical fiber 100 is 1233 nm. The zero dispersion wavelength of the optical fiber 100 is 1427.93 nm. The mode field diameter of the optical fiber 100 is 9.62 µm. The attenuation of the optical fiber 100 at 1310 nm wavelength is 0.205 dB/km and the attenuation at 1550 nm wavelength is 0.187 dB/km. The refractive index ?1 of the first annular region 106 of the optical fiber 100 is 0.56, the refractive index ?2 of the second annular region 108 is 0.068 and refractive index (?) of the ring core is 0.132. The peak shaping parameter alpha of central core region of the optical fiber 100 is 2.96. The optical fiber 100 has a chromatic dispersion of 2.23 ps/nm.km at a wavelength of 1460 nm. The optical fiber 100 has a chromatic dispersion of 6.96 ps/nm.km at a wavelength of 1530 nm. The optical fiber 100 has a chromatic dispersion of 8.29 ps/nm.km at a wavelength of 1550 nm. The optical fiber 100 has a chromatic dispersion of 9.29 ps/nm.km at a wavelength of 1565 nm. The optical fiber 100 has a chromatic dispersion of 13.32 ps/nm.km at a wavelength of 1625 nm. The optical fiber 100 has a maximum macrobending loss of 0.012/1 turn for 32 mm bending radius at wavelength of 1550 nm. The optical fiber 100 has a maximum macrobending loss of 0.011/ 1 turn for 32 mm bending radius at wavelength of 1625 nm.

In another embodiment of the present disclosure, the radius of the first annular region 106 is 2.75 µm, the radius of the second annular region 108 is 6.11 µm and the radius of the third annular region 110 is 9.17 µm. The cable cut-off wavelength of the optical fiber 100 is 1259 nm. The zero dispersion wavelength of the optical fiber 100 is 1424.99 nm. The mode field diameter of the optical fiber 100 is 9.40 µm. The attenuation of the optical fiber 100 at 1310 nm wavelength is 0.205 dB/km and the attenuation of the optical fiber 100 at 1550 nm wavelength is 0.189 dB/km. The refractive index ?1 of first annular region 106 of the optical fiber 100 is 0.59, the refractive index ?2 of second annular region 108 is 0.085 and the refractive index ?3 of the third annular region 110 is 0.126. The peak shaping parameter alpha of the central core region of the optical fiber 100 is 3.58. The optical fiber 100 has a chromatic dispersion of 2.40 ps/nm.km at a wavelength of 1460 nm of the optical fiber 100. The optical fiber 100 has a chromatic dispersion of 6.97 ps/nm.km at a wavelength of 1530 nm. The optical fiber 100 has a chromatic dispersion of 8.23 ps/nm.km at a wavelength of 1550 nm. The optical fiber 100 has a chromatic dispersion of 9.17 ps/nm.km at a wavelength of 1565 nm. The optical fiber 100 has a chromatic dispersion of 13.85 ps/nm.km at a wavelength of 1625 nm. The optical fiber 100 has a maximum macrobending loss of 0.003/ 1 turn for 32 mm bending radius at wavelength of 1550 nm. The optical fiber 100 has a maximum macrobending loss of 0.03/ 1 turn for 32 mm bending radius at wavelength of 1625 nm.

In yet another embodiment of the present disclosure, the radius of the first annular region 106 is 2.90 µm, the radius of the second annular region 108 is 6.42 µm and the radius of the third annular region 110 is 9.48 µm. The cable cut-off wavelength of the optical fiber 100 is 1214 nm. The zero dispersion wavelength of the optical fiber 100 is 1424.36 nm. The mode field diameter of the optical fiber 100 is 9.29 µm. The attenuation of the optical fiber 100 at 1310 nm wavelength is 0.202 dB/km and the attenuation of the optical fiber 100 at 1550 nm wavelength is 0.187 dB/km. The refractive index ?1 of the first annular region 106 of the optical fiber 100 is 0.59, the refractive index ?2 of the second annular region 108 is 0.069 and the refractive index ?3 of the third annular region 110 is 0.141. The peak shaping parameter alpha of the central core region of the optical fiber 100 is 3.2. The optical fiber 100 has a chromatic dispersion of 2.39 ps/nm.km at a wavelength of 1460 nm. The optical fiber 100 has a chromatic dispersion of 6.88 ps/nm.km at a wavelength of 1530 nm. The optical fiber 100 has a chromatic dispersion of 8.129 ps/nm.km at a wavelength of 1550 nm. The optical fiber 100 has a chromatic dispersion of 9.05 ps/nm.km at a wavelength of 1565 nm. The optical fiber 100 has a chromatic dispersion of 12.68 ps/nm.km at a wavelength of 1625 nm. The optical fiber 100 has a maximum macrobending loss of 0.008/ 1 turn for 32 mm bending radius at wavelength of 1550 nm. The optical fiber 100 has a maximum macrobending loss of 0.018/ 1 turn for 32 mm bending radius at wavelength of 1625 nm.

In yet another embodiment of the present disclosure, the radius of the first annular region 106 is 2.90 µm, the radius of the second annular region 108 is 6.42 µm and the radius of the third annular region 110 is 9.63 µm. The cable cut-off wavelength of the optical fiber 100 is 1215.9 nm. The zero dispersion wavelength of the optical fiber 100 is 1426.81 nm. The mode field diameter of the optical fiber 100 is 9.39 µm. The attenuation of the optical fiber 100 at 1310 nm wavelength is 0.201 dB/km and the attenuation at 1550 nm wavelength is 0.187 dB/km. The refractive index ?1 of first annular region 106 of the optical fiber 100 is 0.6, the refractive index ?2 of the second annular region 108 is 0.065 and the refractive index ?3 of the third annular region 110 is 0.153. The peak shaping parameter alpha of the optical fiber 100 is 3.014. The optical fiber 100 has a chromatic dispersion of 2.24 ps/nm.km at a wavelength of 1460 nm. The optical fiber 100 has a chromatic dispersion of 6.74 ps/nm.km at a wavelength of 1530 nm. The optical fiber 100 has a chromatic dispersion of 7.99 ps/nm.km at a wavelength of 1550 nm. The optical fiber 100 has a chromatic dispersion of 8.92 ps/nm.km at a wavelength of 1565 nm. The optical fiber 100 has a chromatic dispersion of 12.58 ps/nm.km at a wavelength of 1625 nm. The optical fiber 100 has a maximum macrobending loss of 0.003/1 turn for 32 mm bending radius at wavelength of 1550 nm. The optical fiber 100 has a maximum macrobending loss of 0.011/ 1 turn for 32 mm bending radius at wavelength of 1625 nm.

In yet another embodiment of the present disclosure, the radius of the first annular region 106 is 2.90 µm, the radius of the second annular region 108 is 6.26 µm and the radius of the third annular region 110 is 9.32 µm. The cable cut-off wavelength of the optical fiber 100 is 1259.6 nm. The zero dispersion wavelength of the optical fiber 100 is 1429.14 nm. The mode field diameter of the optical fiber 100 is 9.19 µm. The attenuation of the optical fiber 100 at 1310 nm wavelength is 0.202 dB/km and the attenuation of the optical fiber 100 at 1550 nm wavelength is 0.188 dB/km. The refractive index ?1 of first annular region 106 of the optical fiber 100 is 0.61, the refractive index ?2 of the second annular region 108 is 0.071 and the refractive index ?3 of the third annular region 110 is 0.149. The peak shaping parameter alpha of the central core region of the optical fiber 100 is 3.044. The optical fiber 100 has a chromatic dispersion of 2.068 ps/nm.km at a wavelength of 1460 nm. The optical fiber 100 has a chromatic dispersion of 6.54 ps/nm.km at a wavelength of 1530 nm. The optical fiber 100 has a chromatic dispersion of 7.78 ps/nm.km at a wavelength of 1550 nm. The optical fiber 100 has a chromatic dispersion of 8.70 ps/nm.km at a wavelength of 1565 nm. The optical fiber 100 has a chromatic dispersion of 12.31 ps/nm.km at a wavelength of 1625 nm. The optical fiber 100 has a maximum macrobending loss of 0.009/1 turn for 32 mm bending radius at wavelength of 1550 nm. The optical fiber 100 has a maximum macrobending loss of 0.019/ 1 turn for 32 mm bending radius at wavelength of 1625 nm.

In yet another embodiment of the present disclosure, the radius of the first annular region 106 is 2.90 µm, the radius of the second annular region 108 is 6.42 µm and the radius of the third annular region 110 is 9.32 µm. The cable cut-off wavelength of the optical fiber 100 is 1190.4 nm. The zero dispersion wavelength of the optical fiber 100 is 1424.94 nm. The mode field diameter of the optical fiber 100 is 9.34 µm. The attenuation of the optical fiber 100 at 1310 nm wavelength is 0.203 dB/km and the attenuation at 1550 nm wavelength is 0.188 dB/km. The refractive index ?1 of first annular region 106 of the optical fiber 100 is 0.58, the refractive index ?2 of the second annular region 108 is 0.068 and the refractive index ?3 of the third annular region 110 is 0.132. The peak shaping parameter alpha of the central core region of the optical fiber 100 is 3.003. The optical fiber 100 has a chromatic dispersion of 2.387 ps/nm.km at a wavelength of 1460 nm. The optical fiber 100 has a chromatic dispersion of 6.92 ps/nm.km at a wavelength of 1530 nm. The optical fiber 100 has a chromatic dispersion of 8.18 ps/nm.km at a wavelength of 1550 nm. The optical fiber 100 has a chromatic dispersion of 9.11 ps/nm.km at a wavelength of 1565 nm. The optical fiber 100 has a chromatic dispersion of 12.78 ps/nm.km at a wavelength of 1625 nm. The optical fiber 100 has a maximum macrobending loss of 0.002/ 1 turn for 32 mm bending radius at wavelength of 1550 nm. The optical fiber 100 has a maximum macrobending loss of 0.008/ 1 turn for 32 mm bending radius at wavelength of 1625 nm.

In yet another embodiment of the present disclosure, the radius of the first annular region 106 is 3.05 µm, the radius of the second annular region 108 is 6.42 µm and the radius of the third annular region 110 is 9.42 µm. The cable cut-off wavelength of the optical fiber 100 is 1200.23 nm. The zero dispersion wavelength of the optical fiber 100 is 1412.6 nm. The mode field diameter of the optical fiber 100 is 9.011 µm. The attenuation of the optical fiber 100 at 1310 nm wavelength is 0.205 dB/km and the attenuation at 1550 nm wavelength is 0.19 dB/km. The refractive index ?1 of first annular region 106 of the optical fiber 100 is 0.64, the refractive index ?2 of the second annular region 108 is 0.074 and the refractive index ?3 of the third annular region 110 is 0.133. The peak shaping parameter alpha of the central core region of the optical fiber 100 is 2.511. The optical fiber 100 has a chromatic dispersion of 3.30 ps/nm.km at a wavelength of 1460 nm. The optical fiber 100 has a chromatic dispersion of 7.38 ps/nm.km at a wavelength of 1530 nm. The optical fiber 100 has a chromatic dispersion of 8.33 ps/nm.km at a wavelength of 1550 nm. The optical fiber 100 has a chromatic dispersion of 8.99 ps/nm.km at a wavelength of 1565 nm. The optical fiber 100 has a chromatic dispersion of 11.02 ps/nm.km at a wavelength of 1625 nm. The optical fiber 100 has a maximum macrobending loss of 0.001/ 1 turn for 32 mm bending radius at wavelength of 1550 nm. The optical fiber 100 has a maximum macrobending loss of 0.002/ 1 turn for 32 mm bending radius at wavelength of 1625 nm.

In yet another embodiment of the present disclosure, the radius of the first annular region 106 is 2.90 µm, the radius of the second annular region 108 is 6.42 µm and the radius of the third annular region 110 is 9.63 µm. The cable cut-off wavelength of the optical fiber 100 is 1251.9 nm. The zero dispersion wavelength of the optical fiber 100 is 1421.4 nm. The mode field diameter of the optical fiber 100 is 9.103 µm. The attenuation of the optical fiber 100 at 1310 nm wavelength is 0.202 dB/km and the attenuation at 1550 nm wavelength is 0.187 dB/km. The refractive index ?1 of first annular region 106 of the optical fiber 100 is 0.607, the refractive index ?2 of the second annular region 108 is 0.071 and the refractive index ?3 of the third annular region 110 is 0.149. The peak shaping parameter alpha of the central core of the optical fiber 100 is 3.724. The optical fiber 100 has a chromatic dispersion of 2.54 ps/nm.km at a wavelength of 1460 nm. The optical fiber 100 has a chromatic dispersion of 6.93 at a wavelength of 1530 nm. The optical fiber 100 has a chromatic dispersion of 8.14 ps/nm.km at a wavelength of 1550 nm. The optical fiber 100 has a chromatic dispersion of 9.04 ps/nm.km at a wavelength of 1565 nm. The optical fiber 100 has a chromatic dispersion of 12.58 ps/nm.km at a wavelength of 1625 nm. The optical fiber 100 has a maximum macrobending loss of 0.002/ 1 turn for 32 mm bending radius at wavelength of 1550 nm. The optical fiber 100 has a maximum macrobending loss of 0.004/ 1 turn for 32 mm bending radius at wavelength of 1625 nm.

In yet another embodiment of the present disclosure, the radius of the first annular region 106 is 2.90 µm, the radius of the second annular region 108 is 6.42 µm and the radius of the third annular region 110 is 9.32 µm. The cable cut-off wavelength of the optical fiber 100 is 1249.56 nm. The zero dispersion wavelength of the optical fiber 100 is 1422.4 nm. The mode field diameter of the optical fiber 100 is 9.14 µm. The attenuation of the optical fiber 100 at 1310 nm wavelength is 0.203 dB/km and the attenuation at 1550 nm wavelength is 0.188 dB/km. The refractive index ?1 of first annular region 106 of the optical fiber 100 is 0.601, the refractive index ?2 of the second annular region 108 is 0.065 and the refractive index ?3 of the third annular region 110 is 0.135. The peak shaping parameter alpha of the central core region of the optical fiber 100 is 3.237. The optical fiber 100 has a chromatic dispersion of 2.512 ps/nm.km at a wavelength of 1460 nm. The optical fiber 100 has a chromatic dispersion of 6.951 ps/nm.km at a wavelength of 1530 nm. The optical fiber 100 has a chromatic dispersion of 8.17 ps/nm.km at a wavelength of 1550 nm. The optical fiber 100 has a chromatic dispersion of 9.09 ps/nm.km at a wavelength of 1565 nm of the optical fiber 100. The optical fiber 100 has a chromatic dispersion of 12.67 ps/nm.km at a wavelength of 1625 nm. The optical fiber 100 has a maximum macrobending loss of 0.002/ 1 turn for 32 mm bending radius at wavelength of 1550 nm. The optical fiber 100 has a maximum macrobending loss of 0.002/ 1 turn for 32 mm bending radius at wavelength of 1625 nm.

In yet another embodiment of the present disclosure, the radius of the first annular region 106 is 2.90 µm, the radius of the second annular region 108 is 6.26 µm and the radius of the third annular region 110 is 9.17 µm. The cable cut-off wavelength of the optical fiber 100 is 1152.11 nm. The zero dispersion wavelength of the optical fiber 100 is 1419.06 nm. The mode field diameter of the optical fiber 100 is 8.95 µm. The attenuation of the optical fiber 100 at 1310 nm wavelength is 0.204 dB/km and the attenuation at 1550 nm wavelength is 0.189 dB/km. The refractive index ?1 of first annular region 106 of the optical fiber 100 is 0.608, the refractive index ?2 of the second annular region 108 is 0.07 and the refractive index ?3 of the third annular region 110 is 0.128. The peak shaping parameter alpha of the central core region of the optical fiber 100 is 3.28. The optical fiber 100 has a chromatic dispersion of 2.708 ps/nm.km at a wavelength of 1460 nm. The optical fiber 100 has a chromatic dispersion of 7.061 ps/nm.km at a wavelength of 1530 nm. The optical fiber 100 has a chromatic dispersion of 8.255 ps/nm.km at a wavelength of 1550 nm. The optical fiber 100 has a chromatic dispersion of 9.138 ps/nm.km at a wavelength of 1565 nm. The optical fiber 100 has a chromatic dispersion of 12.58 at a wavelength of 1625 nm. The optical fiber 100 has a maximum macrobending loss of 0.001/ 1 turn for 32 mm bending radius at wavelength of 1550 nm. The optical fiber 100 has a maximum macrobending loss of 0.001/ 1 turn for 32 mm bending radius at wavelength of 1625 nm.

Further, in an embodiment of the present disclosure, the refractive index profile of the core region of the optical fiber 100 changes from the center of the optical fiber 100 to the radius of the core. Moreover, the refractive index of each of the plurality of regions of the core region has a pre-defined range of value (as stated above in the patent application). In addition, the radius of each of the plurality of regions of the core region has a pre-defined range of value (as mentioned above in the patent application). In an embodiment of the present disclosure, the pre-defined range of value of the refractive index is set to enable minimum dispersion and low macro bending loss along with low cable cut off wavelength.

In an embodiment of the present disclosure, the pre-defined range of value of the refractive index is set to maintain the dispersion and macro bending loss in a pre-defined range or value. The pre-defined range or value is decided based on the ITU-T G.656 standard. Further, in an embodiment of the present disclosure, the pre-defined range of the value of the core radius is optimized to enable the minimum dispersion and low macro bending loss. In addition, each region of the plurality of regions has the corresponding refractive index value.

FIG. 2 illustrates a refractive index profile 200 of the optical fiber 100, in accordance with one of the embodiment of the present disclosure. It may be noted that to explain a graphical appearance of the refractive index profile 200, references will be made to the structural elements of the optical fiber100. The refractive index profile 200 illustrates a relationship between the refractive index of the optical fiber 100 and the radius of the optical fiber 100. In an embodiment of the present disclosure, the refractive index profile 200 shows the change in the refractive index of the optical fiber 100 with the radius of the optical fiber 100. The optical fiber 100 has a single ring core profile with four regions having varying refractive indices and thickness. The first annular region in the optical fiber 100 is the central core region. The central core region in the optical fiber 100 has a alpha profile. The minimum value of alpha of the central core region being 1.66. The maximum value of the alpha of the central core region being 3.84. In an embodiment of the present disclosure, the central core region has a centerline dip. In another embodiment of the present disclosure, the central core region is without the centerline dip. In yet another embodiment of the present disclosure, the centerline dip refers to the dip in the index profile at the center of the optical fiber (without the central core region).

Further, in an embodiment of the present disclosure, the refractive index profile 200 is a curved profile. In an embodiment of the present disclosure, the first annular region 106, the second annular region 108 and the third annular region 110 form a curved profile. In an embodiment of the present disclosure, the fourth annular region 104 forms a straight horizontal line. Further, the refractive index ?1 of the first annular region 106 is in a range of 0.56 to 0.73. In addition, the radius r1 of the first annular region 106 is in a range of 2.75 µm to 3.21 µm.

Furthermore, the refractive index ?2 of the second annular region 108 is in a range of 0.04 to 0.19. In addition, the radius r2 of the second annular region 108 is in a range of 5.20 µm to 6.42 µm. Moreover, the refractive index ?3 of the third annular region 110 is in a range of 0.09 to 0.22. In addition, the radius r3 of the third annular region 110 is in a range of 8.26 µm to 10.09 µm. In an embodiment of the present disclosure, the optical fiber 100 has the peak shaping parameter of the central core region in the range of 1.66 and 3.84.

Furthermore, in an embodiment of the present disclosure, the chromatic dispersion values of the optical fiber 100 are in the range of 1 ps/nm.km to 4.6 ps/nm.km at 1460 nm wavelength. In another embodiment of the present disclosure, the chromatic dispersion values of the optical fiber 100 are in the range of 3.02 ps/nm.km to 8.24 ps/nm.km at 1530 nm wavelength. In yet another embodiment of the present disclosure, the chromatic dispersion values of the optical fiber 100 are in the range of 3.6 ps/nm.km to 9.28 ps/nm.km at 1550 nm wavelength. In yet another embodiment of the present disclosure, the chromatic dispersion values of the optical fiber 100 are in the range of 3.8 ps/nm.km to 10.23 ps/nm.km at 1565 nm wavelength. In yet another embodiment of the present disclosure, the chromatic dispersion values of the optical fiber 100 are in the range of 4.58 ps/nm.km to 13.8 ps/nm.km at 1625 nm wavelength. In yet another embodiment of the present disclosure, the optical fiber has a macrobending loss of less than 0.05 dB/1 turn, preferably less than 0.04 dB/1 turn, more preferably less than 0.03 dB/1 turn and most preferably less than 0.02 dB/1 turn for 32 mm bending diameter at a wavelength of 1550 nm. In yet another embodiment of the present disclosure, the optical fiber has a macrobending loss of less than 0.05 dB/1 turn, preferably less than 0.04 dB/1 turn, more preferably less than 0.03 dB/1 turn and most preferably less than 0.02 dB/1 turn for 32 mm bending diameter at a wavelength of 1625 nm. In yet another embodiment of the present disclosure, the optical fiber has a macrobending loss of less than 0.05 dB/100 turns, preferably less than 0.04 dB/100 turns, more preferably less than 0.03 dB/100 turns and most preferably less than 0.02 dB/100 turns for 60 mm bending diameter at a wavelength of 1550 nm. In yet another embodiment of the present disclosure, the optical fiber has a macrobending loss of less than 0.05 dB/100 turns, preferably less than 0.04 dB/100 turns, more preferably less than 0.03 dB/100 turns and most preferably less than 0.02 dB/100 turns for 60 mm bending diameter at a wavelength of 1625 nm.

In an embodiment of the present disclosure, the refractive index and the radius of the optical fiber 100 are optimized for achieving the pre-defined value of the dispersion and the macro bending loss.

Going further, the present disclosure provides numerous advantages over the prior art. The present disclosure provides the non-zero dispersion shifted optical fiber with the low dispersion. In addition, the present disclosure, the non-zero dispersion shifted optical fiber provides low macro bending losses. Moreover, the present disclosure provides the low dispersion and the low macro bending loss in the single profile. In addition, the present disclosure provides the optical fiber with low cut-off wavelength to operate in O and E bands. In another embodiment of the present disclosure, the optical fiber is operated in S, C and L bands in the wavelength range of 1460 nm and 1625 nm.

The foregoing descriptions of specific embodiments of the present technology have been presented for purposes of illustration and description. They are not intended to be exhaustive or to limit the present technology to the precise forms disclosed, and obviously many modifications and variations are possible in light of the above teaching. The embodiments were chosen and described in order to best explain the principles of the present technology and its practical application, to thereby enable others skilled in the art to best utilize the present technology and various embodiments with various modifications as are suited to the particular use contemplated. It is understood that various omissions and substitutions of equivalents are contemplated as circumstance may suggest or render expedient, but such are intended to cover the application or implementation without departing from the spirit or scope of the claims of the present technology.

While several possible embodiments of the disclosure have been described above and illustrated in some cases, it should be interpreted and understood as to have been presented only by way of illustration and example, but not by limitation. Thus, the breadth and scope of a preferred embodiment should not be limited by any of the above-described exemplary embodiments.