Claims:WE CLAIM:
1. A spectrometer (100) comprising:
a. a light source (102);
b. a pre-dispersing component (104) configured to receive light from said light source (102) and to separate said light into one or more spectral components and further configured to selectively reflect at least one spectral component;
c. a post-dispersing component (106) configured to receive said at least one reflected spectral component and configured to further resolve said at least one reflected spectral component in to resolved one or more spectral components; and
d. a linear array detector (108) having a plurality of pixels, each of said pixels configured to receive said resolved one or more spectral components and further configured to convert said spectral components into electrical signals.
2. The spectrometer (100) as claimed in claim 1, wherein said pre-dispersing component (104) comprising:
a. a first dispersing element (104A) configured to
i. receive said light from said light source (102) via a slit (105); and
ii. separate said light into one or more spectral components,
b. a spatial light intensity modulator (104B) configured to receive one or more spectral components and further configured to facilitate selective reflection or transmission of at least one of said one or more spatial components of interest.
3. The spectrometer (100) as claimed in claim 2, wherein said spatial light intensity modulator (104B) is selected from the group consisting of a digital micro mirror device (DMD), Liquid Crystal On Silicon (LCOS), a fiber optic array, a discrete slit array and the like.
4. The spectrometer (100) as claimed in claim 2, wherein said first dispersing element (104A) is a reflection grating.
5. The spectrometer (100) as claimed in claim 3, wherein said reflection grating is a planar reflection grating.
6. The spectrometer (100) as claimed in claim 1, wherein said post-dispersing component (106) comprises a second dispersing element.
7. The spectrometer (100) as claimed in claim 5, wherein said second dispersing element is an echelle grating (113).
8. The spectrometer (100) as claimed in claims 2 and 5, wherein said first and second dispersing elements are positioned in cross-dispersion direction with respect to each other.
9. The spectrometer (100) as claimed in claim 1, wherein said light source (102) is selected from the group consisting of deuterium lamp, halogen lamp, xenon lamp, LED lamp, arc-spark emission source, inductively coupled plasma emission source and the like.
10. The spectrometer (100) as claimed in claim 1, wherein the wavelength of said light source (102) is in the range 100 nm to 1100 nm.
, Description:FIELD
The present disclosure relates to the field of spectrometers.
DEFINITIONS
As used in the present disclosure, the following terms are generally intended to have the meaning as set forth below, except to the extent that the context in which they are used indicate otherwise.
The expression “Spectrometer” used hereinafter in this specification refers to, but is not limited to, an instrument used to measure reflectance spectra.
The expression “Echelle Grating” used hereinafter in this specification refers to, but is not limited to, a type of diffraction grating characterized by a relatively low groove density, but a groove shape which is optimized for use at high incidence angles and therefore in high diffraction orders.
These definitions are in addition to those expressed in the art.
BACKGROUND
The background information herein below relates to the present disclosure but is not necessarily prior art.
Typically, spectrometers are commonly used to analyze the chemical composition of samples by determining the absorption or attenuation of certain wavelengths of electromagnetic radiation by the sample or samples. The conventional spectrometers include diffraction grating and a linear array detector for determining sample of interest. The light is emitted on a sample and is directed onto the grating to spread the spectral components on the detector for detecting chemical composition of the sample. However, the simultaneous measurement of required wavelength is not feasible in conventional spectrometers. Further, high resolution with selected wavelength on the detector is not possible. Also, the conventional spectrometers are heavy and bulky and costly.
There is, therefore, felt a need of a spectrometer that alleviates the aforementioned drawbacks.
OBJECTS
Some of the objects of the present disclosure, which at least one embodiment herein satisfies, are as follows:
An object of the present disclosure is to provide a spectrometer.
Another object of the present disclosure is to provide a spectrometer that has higher spectral resolution.
Yet another object of the present disclosure is to provide a spectrometer that facilitates fast and simultaneous elemental analysis.
Still another object of the present disclosure is to provide a spectrometer that is less bulky.
Still yet another object of the present disclosure is to provide a spectrometer that is economical.
Yet another object of the present disclosure is to provide a spectrometer that is compact.
Still yet another object of the present disclosure is to provide a spectrometer that takes less time for measurement.
Other objects and advantages of the present disclosure will be more apparent from the following description, which is not intended to limit the scope of the present disclosure.
SUMMARY
The present disclosure envisages a spectrometer. The spectrometer comprises a light source, a pre-dispersing component, a post-dispersing component and a linear array detector. The pre-dispersing component is configured to receive light from the light source and separates the light into one or more spectral components. The pre-dispersing component is further configured to selectively reflect at least one spectral component. The post-dispersing component is configured to receive the at least one reflected spectral component. The post-dispersing component is configured to further resolve the at least one reflected spectral component in to resolved one or more spectral components. The linear array detector is having a plurality of pixels. Each of the pixels is configured to receive the resolved one or more spectral components and is further configured to convert the received spectral components into electrical signals.
In an embodiment, the pre-dispersing component includes a first pre-dispersing element and a spatial light intensity modulator. The first pre-dispersing element configured to receive the light from the light source via a slit and separate the light into one or more spectral components. The spatial light intensity modulator is configured to receive the one or more spectral components. The spatial light intensity modulator is further configured to facilitate selective reflection or transmission of the one or more spatial components of interest.
In an embodiment, the spatial light intensity modulator is selected from the group consisting of a digital micro mirror device (DMD), Liquid Crystal On Silicon (LCOS), a fiber optic array, a discrete slit array and the like.
In an embodiment, the first dispersing element is a reflection grating. In an embodiment, the reflection grating is a planar reflection grating.
In an embodiment, the post-dispersing component comprises a second dispersing element.
In an embodiment, the second dispersing element is an echelle grating.
In an embodiment, the light source is selected from the group consisting of deuterium lamp, halogen lamp, xenon lamp, LED lamp, arc-spark emission source, inductively coupled plasma emission source and the like.
In an embodiment, the wavelength of the light source is in the range 100 nm to 1100 nm.
In an embodiment, the first and the second dispersing elements are positioned in cross-dispersion direction with respect to each other.
BRIEF DESCRIPTION OF ACCOMPANYING DRAWING
A spectrometer of the present disclosure will now be described with the help of the accompanying drawing, in which:
FIGURE 1 illustrates a schematic view of optical configuration of the spectrometer;
FIGURE 2 illustrates a block diagram of the spectrometer of Figure 1;
FIGURES 3 illustrates wide band light source of 200 nm to 800 nm falls on the entrance slit of Figure 1;
FIGURE 4 illustrates predispersed spectrum of the light source of FIGURE 3 falling on the digital micro mirror array;
FIGURE 5 illustrates three micro mirrors a, b and c which are turned ON and reflecting three discrete wavelengths;
FIGURE 6 illustrates echelle grating dispersing selected wavelengths with higher resolution; and
FIGURE 7 illustrates linear array detector receiving the three wavelengths.
LIST OF REFERENCE NUMERALS
100 – Spectrometer
102 – Light Source
104 – Pre-Dispersing Component
104A – First Dispersing Element
104B – Digital Micro Mirror Device (DMD)
105 – Slit
106 – Post-Dispersing Component
108 – Linear Array Detector
109 – First Collimating Mirror
110 – First Focusing Mirror
111 – Second Focusing Mirror
112 – Second Collimating Mirror
113 – Echelle Grating
DETAILED DESCRIPTION
Embodiments, of the present disclosure, will now be described with reference to the accompanying drawing.
Embodiments are provided so as to thoroughly and fully convey the scope of the present disclosure to the person skilled in the art. Numerous details, are set forth, relating to specific components, and methods, to provide a complete understanding of embodiments of the present disclosure. It will be apparent to the person skilled in the art that the details provided in the embodiments should not be construed to limit the scope of the present disclosure. In some embodiments, well-known processes, well-known apparatus structures, and well-known techniques are not described in detail.
The terminology used, in the present disclosure, is only for the purpose of explaining a particular embodiment and such terminology shall not be considered to limit the scope of the present disclosure. As used in the present disclosure, the forms "a,” "an," and "the" may be intended to include the plural forms as well, unless the context clearly suggests otherwise. The terms "comprises," "comprising," “including,” and “having,” are open ended transitional phrases and therefore specify the presence of stated features, integers, steps, operations, elements, modules, units and/or components, but do not forbid the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof. The particular order of steps disclosed in the method and process of the present disclosure is not to be construed as necessarily requiring their performance as described or illustrated. It is also to be understood that additional or alternative steps may be employed.
When an element is referred to as being "mounted on," “engaged to,” "connected to," or "coupled to" another element, it may be directly on, engaged, connected or coupled to the other element. As used herein, the term "and/or" includes any and all combinations of one or more of the associated listed elements.
The terms first, second, third, etc., should not be construed to limit the scope of the present disclosure as the aforementioned terms may be only used to distinguish one element, component, region, layer or section from another component, region, layer or section. Terms such as first, second, third etc., when used herein do not imply a specific sequence or order unless clearly suggested by the present disclosure.
Terms such as “inner,” “outer,” "beneath," "below," "lower," "above," "upper," and the like, may be used in the present disclosure to describe relationships between different elements as depicted from the figures.
The conventional spectrometers are bulky and take much time for measurement of spectral component. Further, the conventional spectrometers are not suitable for simultaneous analysis of spectral components with higher resolution.
Therefore, the present disclosure envisages a spectrometer that obviates the aforementioned drawbacks. The spectrometer (herein after referred to as “spectrometer 100”) is described below with reference to Figures 1 to Figure 7.
The spectrometer 100 comprises a light source 102, a pre-dispersing component 104, a post-dispersing component 106 and a linear array detector 108.
The pre-dispersing component 104 is configured to receive light from the light source 102. The pre-dispersing component 104 separates the light into one or more spectral components. The pre-dispersing component 104 is further configured to selectively reflect at least one spectral component of interest. The pre-dispersing component 104 includes a first pre-dispersing element 104A and a spatial light intensity modulator 104B.
The light source 102 is configured to emit light which is incident on the pre-dispersing component 104 through a slit 105. In an embodiment, the light source 102 is selected from the group consisting of deuterium lamp, halogen lamp, xenon lamp, LED lamp, arc-spark emission source, inductively coupled plasma emission source and the like. In an embodiment, the wavelength of the light source 102 is in the range of 100 nm to 1100 nm.
The light emitted by the light source 102 is collimated by the first collimating mirror 109.
The collimated light is then focused on a first focusing mirror 110 and is then reflected on the digital micro mirror device 104B. More particularly, the first dispersing element 104A is configured to receive the collimated light reflected from the first collimating mirror 109 and is further configured to separate the received light into one or more spectral components. In an embodiment, the first dispersing element 104A is a reflection grating. More particularly, the first dispersing element 104A is a planar reflection grating.
The spatial light intensity modulator 104B comprises either a plurality of micro-mirrors or a shutter mechanism operatively configured thereon. Each of the plurality of micro-mirrors or the shutter mechanism is configured to receive one or more spectral components from the first dispersing element 104A. Each of the plurality of micro-mirrors or the shutter mechanism spatial light intensity modulator 104B is switchable between a first position and a second position i.e. either ON or OFF. When turned ON it facilitates selective reflection of one or more spatial components of interest and when turned OFF it facilitates selective light blocking of one or more spatial components of interest.
The post-dispersing component 106 is configured to receive the at least one reflected spatial component from the spatial light intensity modulator 104B. The post-dispersing component 106 is further configured to separate the at least one reflected spatial component in to further resolved one or more spatial components. In an embodiment, the post-dispersing component 106 comprises a second dispersing element i.e. an echelle grating 113.
The post-dispersing component 106 includes a second collimating mirror 112 configured to collimate resolved spatial components and reflects the same onto the echelle grating 113. The echelle grating 113 disperses the spatial components onto the second focusing mirror 111 to reflect the same onto the linear array detector 108.
The first dispersing 104A and the second dispersing element 113 are positioned in cross-dispersion direction with respect to each other, as depicted in Figure 1. The advantage of this arrangement is that it eliminates the higher order spectra from reaching the linear array detector 108, thereby eliminating errors in readings.
The linear array detector 108 is configured to receive the resolved one or more spectral component. The linear array detector 108 is having a plurality of pixels. Each of the pixels is configured to receive the resolved one or more spectral components and is further configured to convert the received resolved one or more spatial components into electrical signals for further analysis.
In an operative configuration, the light from the light source 102 passes through the slit 105 and is incident on the pre-dispersing component 104. More particularly onto the first collimating mirror 109 to collimate the received light. The collimated light is then reflected onto the planar grating 104A by the first focusing mirror 110. The reflected light is then separated one or more spectral components by the planar grating 104A and are reflected on to the spatial light intensity modulator 104B. The spatial light intensity modulator 104B is configured to provide selective reflection to the desired one or more spatial components onto the post-dispersing components 106. The second collimating mirror 112 receives the selected one or more spatial components and collimates the selected one or more spatial components. The collimated spatial components are reflected onto the second dispersing element i.e. echelle grating 113 for further resolving the spatial components. The linear array detector 108 is configured to receive the resolved spatial component to convert the spatial component of interest in electrical signals for further analysis.
In an exemplary embodiment as depicted in Figure 3 to Figure 7, the light source 102 having wavelength in the range of 200 nm to 800 nm is passed through the slit 105 having a finite height ‘h’ of about 10 mm and width ‘w’ of about 10 micron, as shown in Figure 3. This height and width facilitates the amount of the light impinging on the pre-dispersing component 104 where it disperses light single dimensional spectral component having low resolution. The height of the slit 105 is proportional to the height of the spatial light intensity modulator 104B i.e. digital micro mirror device (DMD). The DMD has plurality of micro mirrors embedded therein that turn ON or turn OFF. The slit 105 disperses the spectral component in the form of an image dispersed on to the plane of the DMD via the pre-dispersing component 104 in the Y-direction only and no dispersion in the X-direction as shown in Figure 4. Further, as shown in Figure 5, the DMD receives the pre-dispersing component in the Y-direction and is programmed such that by selecting a particular wavelength, it turns ON particular mirrors i.e. mirrors a, b and c and the mirrors other than a, b and c are turned OFF. The DMD then reflects particular wavelengths having finite spectral width at a particular height of the post-dispersing component 106 i.e. onto the echelle grating 113. After receiving the image of a particular wavelength and particular height, the echelle grating 113 cross disperses the spatial components in only the X-direction and the same is depicted in Figure 6. The three spatial components are dispersed by the echelle grating 113 and are highly resolved components. As shown in Figure 7, this selected wavelength of the three spatial components are reflected on to the one dimensional linear array detector 108 where it receives the three spatial components in the Y-direction and only a small portion of spatial component in the X-direction.
Thus, the DMD 104B of the spectrometer 100 facilitates simultaneous elemental analysis along with the drift correction and allows selection of desired spectral components. The spectrometer 100 is economical and is less bulky and provides measurement within less time as compared to conventional spectrometers.
TECHNICAL ADVANCES AND ECONOMICAL SIGNIFICANCE
The present disclosure described herein above has several technical advantages including, but not limited to, the realization of a spectrometer, that:
• has higher spectral resolution;
• facilitates fast and simultaneous elemental analysis;
• is less bulky;
• is economical;
• takes less time for measurement; and
• is compact.
The foregoing description of the specific embodiments so fully reveals the general nature of the embodiments herein that others can, by applying current knowledge, readily modify and/or adapt for various applications such specific embodiments without departing from the generic concept, and, therefore, such adaptations and modifications should and are intended to be comprehended within the meaning and range of equivalents of the disclosed embodiments. It is to be understood that the phraseology or terminology employed herein is for the purpose of description and not of limitation. Therefore, while the embodiments herein have been described in terms of preferred embodiments, those skilled in the art will recognize that the embodiments herein can be practiced with modification within the spirit and scope of the embodiments as described herein.
Throughout this specification the word “comprise”, or variations such as “comprises” or “comprising”, will be understood to imply the inclusion of a stated element, integer or step, or group of elements, integers or steps, but not the exclusion of any other element, integer or step, or group of elements, integers or steps.
The use of the expression “at least” or “at least one” suggests the use of one or more elements or ingredients or quantities, as the use may be in the embodiment of the disclosure to achieve one or more of the desired objects or results.
Any discussion of documents, acts, materials, devices, articles or the like that has been included in this specification is solely for the purpose of providing a context for the disclosure. It is not to be taken as an admission that any or all of these matters form a part of the prior art base or were common general knowledge in the field relevant to the disclosure as it existed anywhere before the priority date of this application.
While considerable emphasis has been placed herein on the components and component parts of the preferred embodiments, it will be appreciated that many embodiments can be made and that many changes can be made in the preferred embodiments without departing from the principles of the disclosure. These and other changes in the preferred embodiment as well as other embodiments of the disclosure will be apparent to those skilled in the art from the disclosure herein, whereby it is to be distinctly understood that the foregoing descriptive matter is to be interpreted merely as illustrative of the disclosure and not as a limitation.