Claims:STATEMENT OF CLAIMS
We claim:
1. An optical fibre (100) comprising:
a core (102), wherein the core (102) has a first relative refractive index ?1, wherein the first relative refractive index ?1 of the core (102) is in a range of about 0 to 0.12;
a first trench region (106), wherein the first trench region (106) has a relative refractive index ?3, wherein the first trench region has a first alpha atrench-1;
a second trench region (108), wherein the second trench region (108) is adjacent to the first trench region (106), wherein the second trench region (108) has a relative refractive index ?4, wherein the second trench region has a second alpha atrench-2; and
a cladding region (110), wherein the cladding region (110) surrounds the second trench region (108),
wherein the optical fibre 100 has attenuation of less than or equal to 0.17 dB/km at a wavelength of 1550 nanometer, wherein the optical fibre (100) has a mode field diameter in a range of about 12 micron to 13 micron,
wherein the optical fibre (100) has gradual variation in core and trench regions of refractive index profile.
2. The optical fibre (100) as claimed in claim 1, wherein the optical fibre (100) has at least one of macrobend loss up to 0.1 decibel per 100 turns corresponding to wavelength of 1550 nanometer at bending radius of about 30 millimeter and macrobend loss up to 0.1 decibel per 100 turns corresponding to wavelength of 1625 nanometer at bending radius of about 30 millimeter.

3. The optical fibre (100) as claimed in claim 1, wherein the optical fibre (100) has chromatic dispersion in range of about 17 pico second per nanometer-kilometer to 23 pico second per nanometer-kilometer at wavelength of 1550 nanometer, wherein the optical fibre (100) has a cable cut off wavelength up to 1530 nanometer.

4. The optical fibre (100) as claimed in claim 1, further comprising a buffer clad region (104), wherein the buffer clad region (104) has a second relative refractive index ?2, wherein the buffer clad region (104) separates the core (102) and the first trench region (106).

5. The optical fibre (100) as claimed in claim 1, wherein the core (102) has a first radius r1, wherein the first radius r1 is in range of at least one of 2.5 micron to 5 micron and 2 micron to 3.15 micron.

6. The optical fibre (100) as claimed in claim 1, further comprising a buffer clad region (104), wherein the buffer clad region (104) has a second radius r2, wherein the second radius r2 is in range of at least one of 5 micron to 7 micron and 3 micron to 6 micron, wherein the buffer clad region (104) has a second relative refractive index ?2 of about 0.

7. The optical fibre (100) as claimed in claim 1, wherein the cladding region (110) has a fifth radius r5, wherein the fifth radius r5 is about 62.5 micron, wherein the cladding region (110) has a third relative refractive index ?5 of about 0.

8. The optical fibre (100) as claimed in claim 1, wherein the first trench region (106) has a third radius r3, wherein the third radius r3 is in range of at least one of 12 micron to 16 micron and 12 micron to 20 micron, wherein the relative refractive index ?3 is in range of at least one of -0.25 to -0.35 and -0.3 to -0.46, wherein the first alpha atrench-1 of the first trench region (106) is in a range of at least one of about 3 to 6 and 1.5 to 2.

9. The optical fibre (100) as claimed in claim 1, wherein the second trench region (108) has a fourth radius r4, wherein the fourth radius r4 is in range of at least one of 24 micron to 28 micron and 26 micron to 30 micron, wherein the relative refractive index ?4 is in range of at least one of -0.4 to -0.55 and -0.41 to -0.57, wherein the second alpha atrench-2 of the second trench region (108) is in a range of at least one of 3 to 6 and 5 to 9.

10. The optical fibre (100) as claimed in claim 1, wherein the relative refractive index ?4 is greater than the relative refractive index ?3.

11. An optical fibre (100) comprising:
a core (102), wherein the core (102) has a first relative refractive index ?1, wherein the first relative refractive index ?1 of the core (102) is in a range of about 0 to 0.12;
a first trench region (106), wherein the first trench region (106) has a relative refractive index ?3, wherein first trench region has a first alpha atrench-1;
a second trench region (108), wherein the second trench region (108) is adjacent to the first trench region (106), wherein the second trench region (108) has a relative refractive index ?4, wherein the second trench region has a second alpha atrench-2, wherein the relative refractive index ?4 is greater than the relative refractive index ?3; and
a cladding region (110), wherein the cladding region (110) surrounds the second trench region (108),
wherein The optical fibre 100 has attenuation of less than or equal to 0.17 dB/km at a wavelength of 1550 nanometer, wherein the optical fibre (100) has a mode field diameter in a range of about 12 micron to 13 micron,
wherein the optical fibre (100) has gradual variation in core and trench regions of refractive index profile.

12. The optical fibre (100) as claimed in claim 11, wherein the optical fibre (100) has at least one of macrob end loss up to 0.1 decibel per 100 turns corresponding to wavelength of 1550 nanometer at bending radius of about 30 millimeter and macrobend loss up to 0.1 decibel per 100 turns corresponding to wavelength of 1625 nanometer at bending radius of about 30 millimeter.

13. The optical fibre (100) as claimed in claim 11, wherein the optical fibre (100) has chromatic dispersion in range of about 17 pico second per nanometer-kilometer to 23 pico second per nanometer-kilometer at wavelength of 1550 nanometer, wherein the optical fibre (100) has a cable cut off wavelength up to 1530 nanometer.

14. The optical fibre (100) as claimed in claim 11, further comprising a buffer clad region (104), wherein the buffer clad region (104) has a second relative refractive index ?2, wherein the buffer clad region (104) separates the core (102) and the first trench region (106).

15. The optical fibre (100) as claimed in claim 11, wherein the core (102) has a first radius r1, wherein the first radius r1 is in range of at least one of 2.5 micron to 5 micron and 2 micron to 3.15 micron.

16. The optical fibre (100) as claimed in claim 11, further comprising a buffer clad region (104), wherein the buffer clad region (104) has a second radius r2, wherein the second radius r2 is in range of at least one of 5 micron to 7 micron and 3 micron to 6 micron, wherein the buffer clad region (104) has a second relative refractive index ?2 of about 0.

17. The optical fibre (100) as claimed in claim 11, wherein the cladding region (110) has a fifth radius r5, wherein the fifth radius r5 is about 62.5 micron, wherein the cladding region (110) has a third relative refractive index ?5 of about 0.

18. The optical fibre (100) as claimed in claim 11, wherein the first trench region (106) has a third radius r3, wherein the third radius r3 is in range of at least one of 12 micron to 16 micron and 12 micron to 20 micron, wherein the relative refractive index ?3 is in range of at least one of -0.25 to -0.35 and -0.3 to -0.46, wherein the first alpha atrench-1 of the first trench region (106) is in a range of at least one of about 3 to 6 and 1.5 to 2.

19. The optical fibre (100) as claimed in claim 11, wherein the second trench region (108) has a fourth radius r4, wherein the fourth radius r4 is in range of at least one of 24 micron to 28 micron and 26 micron to 30 micron, wherein the relative refractive index ?4 is in range of at least one of -0.4 to -0.55 and -0.41 to -0.57, wherein the second alpha atrench-2 of the second trench region (108) is in a range of at least one of 3 to 6 and 5 to 9.

Dated this 29th Day of July, 2019
Signatures:
Name: Arun Kishore Narasani
Patent Agent: IN/PA/1049

, Description:TECHNICAL FIELD
The present disclosure relates to the field of optical fibre. Particularly, the present disclosure relates to a cutoff shifted optical fibre with high mode field diameter.
BACKGROUND
With the advancement of science and technology, various modern technologies are being employed for communication purposes. One of the most important modern communication technologies is optical fibre communication technology using a variety of optical fibres. Optical fibre is used to transmit information as light pulses from one end to another. The telecommunication industry is continuously striving for designs to achieve high optical signal to noise ratio and low losses. The ongoing research suggests that the optical fibre of G.654.E category is an improved version of G.654.B and an alternative to G.652.D that faces challenges in 400G transmission in territorial long haul communication due to non-linear effects. In addition, major challenges in 400G long haul communication are due to non-linear effects, low optical signal to noise ratio and high attenuation.

In light of the above stated discussion, there is a need for an optical fibre that overcomes the above sited drawbacks.

OBJECT OF THE DISCLOSURE

A primary object of the present disclosure is to provide an optical fibre with large mode field diameter.

Yet another object of the present disclosure is to provide the optical fibre with low loss.

SUMMARY

In an aspect, the present disclosure provides an optical fibre. The optical fibre includes a core. In addition, the optical fibre includes a first trench region. Further, the optical fibre includes a second trench region. Furthermore, the optical fibre a cladding region. The core has a first relative refractive index ?1. The first relative refractive index ?1 of the core is in a range of about 0 to 0.12. Moreover, the first trench region is defined by a relative refractive index ?3. The first trench region has a first alpha atrench-1. The second trench region is adjacent to the first trench region. The second trench region has a relative refractive index ?4. Also, the second trench region has a second alpha atrench-2. The cladding region surrounds the second trench region. The optical fibre 100 has attenuation of less than or equal to 0.17 dB/km at a wavelength of 1550 nanometer. The optical fibre has a mode field diameter in a range of about 12 micron to 13 micron. The optical fibre has gradual variation in core and trench regions of the refractive index profile.

In an embodiment of the present disclosure, the optical fibre has macrobend loss up to 0.1 decibel per 100 turns corresponding to wavelength of 1550 nanometer at bending radius of about 30 millimeter and macro bend loss up to 0.1 decibel per 100 turns corresponding to wavelength of 1625 nanometer at bending radius of about 30 millimeter.

In an embodiment of the present disclosure, the optical fibre has chromatic dispersion in range of about 17 pico second per nanometer-kilometer to 23 pico second per nanometer-kilometer at wavelength of 1550 nanometer. In addition, the optical fibre has a cable cut off wavelength up to 1530 nanometer.

In an embodiment of the present disclosure, the optical fibre further includes a buffer clad region. The buffer clad region is defined by a second relative refractive index ?2. In addition, the buffer clad region separates the core and the first trench region.

In an embodiment of the present disclosure, the core has a first radius r1. The first radius r1 is in range of at least one of 2.5 micron to 5 micron and 2 micron to 3.15 micron.

In an embodiment of the present disclosure, the optical fibre further includes a buffer clad region. The buffer clad region has a second radius r2. The second radius r2 is in range of at least one of 5 micron to 7 micron and 3 micron to 6 micron. The buffer clad region has a second relative refractive index ?2 of about 0.

In an embodiment of the present disclosure, the cladding region has a fifth radius r5. The fifth radius r5 is about 62.5 micron. The cladding region has a third relative refractive index ?5 of about 0.

In an embodiment of the present disclosure, the first trench region has a third radius r3. The third radius r3 is in range of at least one of 12 micron to 16 micron and 12 micron to 20 micron. The relative refractive index ?3 is in range of at least one of -0.25 to -0.35 and -0.3 to -0.46. The first alpha atrench-1 of the first trench region is in a range of at least one of about 3 to 6 and 1.5 to 2.

In an embodiment of the present disclosure, the second trench region has a fourth radius r4. The fourth radius r4 is in range of at least one of 24 micron to 28 micron and 26 micron to 30 micron. The relative refractive index ?4 is in range of at least one of -0.4 to -0.55 and -0.41 to -0.57. The second alpha atrench-2 of the second trench region is in a range of at least one of 3 to 6 and 5 to 9.

In an embodiment of the present disclosure, the relative refractive index ?4 of the second trench region is greater than the relative refractive index ?3 of the first trench region.

In another aspect, the present disclosure provides an optical fibre. The optical fibre includes a core. In addition, the optical fibre includes a first trench region. Further, the optical fibre includes a second trench region. Furthermore, the optical fibre a cladding region. The core has a first relative refractive index ?1. The first relative refractive index ?1 of the core is in a range of 0 to 0.12. Moreover, the first trench region has a relative refractive index ?3. The first trench region has a first alpha atrench_1. The second trench region is adjacent to the first trench region. The second trench region has a relative refractive index ?4. Also, the second trench region has the second alpha atrench-2. The relative refractive index ?4 is greater than the relative refractive index ?3. The cladding region surrounds the second trench region. The optical fibre 100 has attenuation of less than or equal to 0.17 dB/km at a wavelength of 1550 nanometer. The optical fibre has a mode field diameter in a range of about 12 micron to 13 micron. The optical fibre has gradual variation in core and trench regions of refractive index profile.

In an embodiment of the present disclosure, the optical fibre has macrobend loss up to 0.1 decibel per 100 turns corresponding to wavelength of 1550 nanometer at bending radius of about 30 millimeter and macrobend loss up to 0.1 decibel per 100 turns corresponding to wavelength of 1625 nanometer at bending radius of about 30 millimeter.

In an embodiment of the present disclosure, the optical fibre has chromatic dispersion in range of about 17 pico second per nanometer-kilometer to 23 pico second per nanometer-kilometer at wavelength of 1550 nanometer. In addition, the optical fibre has a cable cut off wavelength up to 1530 nanometer.

In an embodiment of the present disclosure, the optical fibre further includes a buffer clad region. The buffer clad region has a second relative refractive index ?2. In addition, the buffer clad region separates the core and the first trench region.

In an embodiment of the present disclosure, the core has a first radius r1. The first radius r1 is in range of at least one of 2.5 micron to 5 micron and 2 micron to 3.15 micron.

In an embodiment of the present disclosure, the optical fibre further includes a buffer clad region. The buffer clad region has a second radius r2. The second radius r2 is in range of at least one of 5 micron to 7 micron and 3 micron to 6 micron. The buffer clad region has a second relative refractive index ?2 of about 0.

In an embodiment of the present disclosure, the cladding region has a fifth radius r5. The fifth radius r5 is about 62.5 micron. The cladding region has a third relative refractive index ?5 of about 0.

In an embodiment of the present disclosure, the first trench region has a third radius r3. The third radius r3 is in range of at least one of 12 micron to 16 micron and 12 micron to 20 micron. The relative refractive index ?3 is in range of at least one of -0.25 to -0.35 and -0.3 to -0.46. The first alpha atrench-1 of the first trench region is in a range of at least one of about 3 to 6 and 1.5 to 2.

In an embodiment of the present disclosure, the second trench region has a fourth radius r4. The fourth radius r4 is in range of at least one of 24 micron to 28 micron and 26 micron to 30 micron. The relative refractive index ?4 is in range of at least one of -0.4 to -0.55 and -0.41 to -0.57. The second alpha atrench-2 of the second trench region is in a range of at least one of 3 to 6 and 5 to 9.

STATEMENT OF THE DISCLOSURE

The present disclosure relates to an optical fibre. The optical fibre includes a core. In addition, the optical fibre includes a first trench region. Further, the optical fibre includes a second trench region. Furthermore, the optical fibre includes a cladding region. The core has a first relative refractive index ?1. The first relative refractive index ?1 of the core is in a range of about 0 to 0.12. Moreover, the first trench region has a relative refractive index ?3. The first trench region has a first alpha atrench-1. The second trench region is adjacent to the first trench region. The second trench region has a relative refractive index ?4. Also, the second trench region has a second alpha atrench-2. The cladding region surrounds the second trench region. The optical fibre 100 has attenuation of less than or equal to 0.17 dB/km at a wavelength of 1550 nanometer. The optical fibre has a mode field diameter in a range of about 12 micron to 13 micron. The optical fibre has gradual variation in core and trench regions of refractive index profile.

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

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

FIG. 2 illustrates a refractive index profile of the optical fibre, in accordance with various embodiments 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

Reference will now be made in detail to selected embodiments of the present disclosure in conjunction with accompanying figures. The embodiments described herein are not intended to limit the scope of the disclosure, and the present disclosure should not be construed as limited to the embodiments described. This disclosure may be embodied in different forms without departing from the scope and spirit of the disclosure. It should be understood that the accompanying figures are intended and provided to illustrate embodiments of the disclosure described below and are not necessarily drawn to scale. In the drawings, like numbers refer to like elements throughout, and thicknesses and dimensions of some components may be exaggerated for providing better clarity and ease of understanding.

It should be noted that the terms "first", "second", and the like, herein do not denote any order, ranking, quantity, or importance, but rather are used to distinguish one element from another. Further, the terms "a" and "an" herein do not denote a limitation of quantity, but rather denote the presence of at least one of the referenced item.

FIG. 1 illustrates a cross-sectional view of an optical fibre 100, in accordance with various embodiments of the present disclosure. In general, optical fibre is a thin strand of glass or plastic capable of transmitting optical signals. In an embodiment of the present disclosure, the optical fibre 100 is configured to transmit information over long distances with high optical signal to noise ratio, low non-linear effects, low latency and low attenuation. The optical fibre 100 of the present disclosure is fully compliant with the requirement of ITU (International Telecommunication Union- Telecommunication Standardization Sector)-G.654 E standard.

The optical fibre 100 includes a core 102, a buffer clad region 104, a first trench region 106, a second trench region 108 and a cladding region 110. In general, core is an inner part of an optical fibre and cladding is an outer part of the optical fibre. In an embodiment of the present disclosure, the core 102 is defined along a central longitudinal axis 112 of the optical fibre 100. The central longitudinal axis 112 is an imaginary axis passing through center of the optical fibre 100.

In an embodiment of the present disclosure, the core 102 of the optical fibre 100 has a first relative refractive index ?1. In general, relative refractive index is a measure of relative difference in refractive index between the two regions. In an embodiment of the present disclosure, refractive index profile determines relationship between refractive index of the optical fibre 100 and radius of the optical fibre 100. In an embodiment of the present disclosure, manufacturing of the optical fibre 100 is carried out after manufacturing of a preform. Further, the refractive index profile of the optical fibre 100 is determined during manufacturing of the preform of the optical fibre 100.

The expression used for calculating the relative refractive index is produced below:

?i=100×((n_i^2-n_clad^2)/(2×n_i^2 ))

wherein, nclad: refractive index of the pure silica;
ni: refractive index of the ith layer;
?i: the relative refractive index of the ith layer.

In addition, the core 102 has maximum refractive index nmax. In an embodiment of the present disclosure, the core 102 has the first relative refractive index ?1 in range of about 0 to 0.12. In another embodiment of the present disclosure, the core 102 has the first relative refractive index ?1 in range of about 0 to 0.1. In yet another embodiment of the present disclosure, range of the first relative refractive index ?1 of the core 102 of the optical fibre 100 may vary.

Further, the core 102 has profile shape parameter a (alpha). In an embodiment of the present disclosure, parameter alpha a is in range of about 4 to 9 for the core 102 of the optical fibre 100. In another embodiment of the present disclosure, parameter alpha a is in range of about 5 to 9 for the core 102 of the optical fibre 100. In yet another embodiment of the present disclosure, range of parameter alpha a of the core 102 of the optical fibre 100 may vary.

Furthermore, the core 102 of the optical fibre 100 has a first radius r1. In an embodiment of the present disclosure, the first radius r1 is in range of about 2.5 micron to 5 micron. In another embodiment of the present disclosure, the first radius r1 is in range of about 2 micron to 3.15 micron. In yet another embodiment of the present disclosure, range of the first radius r1 of the core 102 of the optical fibre 100 may vary.

The optical fibre 100 includes the buffer clad region 104. The buffer clad region 104 concentrically surrounds the core 102 of the optical fibre 100. In an embodiment of the present disclosure, the buffer clad region 104 lies between the first radius r1 and a second radius r2 from the central longitudinal axis 112 of the optical fibre 100. The buffer clad region 104 has a second relative refractive index ?2. In an embodiment of the present disclosure, the buffer clad region 104 has the second relative refractive index ?2 of zero. In another embodiment of the present disclosure, the second relative refractive index ?2 of the buffer clad region 104 may vary.

The buffer clad region 104 has the second radius r2. In an embodiment of the present disclosure, the second radius r2 is in range of about 5 micron to 7 micron. In another embodiment of the present disclosure, the second radius r2 is in range of about 3 micron to 6 micron. In yet another embodiment of the present disclosure, range of the second radius r2 may vary.

The optical fibre 100 includes the first trench region 106. In addition, the first trench region 106 concentrically surrounds the buffer clad region 104 of the optical fibre 100. The first trench region 106 has a relative refractive index ?3. In an embodiment of the present disclosure, the relative refractive index ?3 of the first trench region 106 is in range of about -0.25 to -0.35. In another embodiment of the present disclosure, the relative refractive index ?3 of the first trench region 106 is in range of about -0.3 to 0.46. In yet another embodiment of the present disclosure, range of the relative refractive index ?3 of the first trench region 106 may vary.

In an embodiment of the present disclosure, the first trench region 106 has a first alpha atrench-1 in range of about 3 to 6. In another embodiment of the present disclosure, the first trench region 106 has the first alpha atrench-1 in range of 1.5 to 2. In yet another embodiment of the present disclosure, range of the first alpha atrench-1 of the first trench region 106 may vary.

The first trench region 106 has a third radius r3. The third radius r3 is in range of at least one of 12 micron to 16 micron and 12 micron to 20 micron. In another embodiment of the present disclosure, range of the third radius r3 may vary.

The optical fibre 100 includes the second trench region 108. In addition, the second trench region 108 lies between the third radius r3 and a fourth radius r4. Further, the second trench region 108 concentrically surrounds the first trench region 106 of the optical fibre 100. Furthermore, the second trench region 108 has a relative refractive index ?4. In an embodiment of the present disclosure, the second trench region 108 has the relative refractive index ?4 in range of about -0.4 to -0.55. In another embodiment of the present disclosure, the second trench region 108 has the relative refractive index ?4 in range of about -0.41 to -0.57. In yet another embodiment of the present disclosure, range of the relative refractive index ?4 of the second trench region 100 may vary.

In addition, the second trench region 108 has a second alpha atrench-2. In an embodiment of the present disclosure, second trench region 108 has the second alpha atrench-2 in range of about 3 to 6. In another embodiment of the present disclosure, the second trench region 108 has the second alpha atrench-2 in range of about 5 to 9. In yet another embodiment of the present disclosure, range of the second alpha atrench-2 of the second trench region 108 may vary.

The second trench region 108 has the fourth radius r4. The fourth radius r4 is in range of at least one of 24 micron to 28 micron and 26 micron to 30 micron. In an embodiment of the present disclosure, range of the fourth radius r4 may vary.

The optical fibre 100 includes the cladding region 110. The cladding region 110 concentrically surrounds the second trench region 108 of the optical fibre 100. In addition, the cladding region 110 lies between the fourth radius r4 and a fifth radius r5. Further, the cladding region 110 has a third relative refractive index ?5. In an embodiment of the present disclosure, the cladding region 110 has the third relative refractive index ?5 of about zero. In another embodiment of the present disclosure, the third relative refractive index ?5 of the cladding region 110 may vary.

The cladding region 110 has the fifth radius r5. In an embodiment of the present disclosure, the fifth radius r5 is about 62.5 micron. In another embodiment of the present disclosure, the fifth radius r5 may vary.

The optical fibre 100 has gradual variation in core and trench regions of refractive index profile. In addition, gradual variation means that there is no sharp change in the refractive index profile of the optical fibre 100.

In an embodiment of the present disclosure, the core 102 of the optical fibre 100 has maximum refractive index nmax. The buffer clad region 104 has refractive index of pure silica nclad. The first trench region 106 has minimum refractive index ntrench-1. In addition, ntrench-1 is minimum refractive index of the first trench region 106. The second trench region 108 has minimum refractive index ntrench-2. In addition, ntrench-2 is minimum refractive index of the second trench region 108. Furthermore, expressions used to determine refractive index is given below:

n(r)=n_max [1-2?1(r/r1)^a ]^0.5
for r = r1
n(r)=n_clad
for r1 = r