WO2017149397A1

WO2017149397A1 - System for measuring optical parameters of materials

Info

Publication number: WO2017149397A1
Application number: PCT/IB2017/050028
Authority: WO
Inventors: Hanumesh Kumar DASARI; Nagaraja Chiyedu
Original assignee: Dasari Hanumesh Kumar; Nagaraja Chiyedu
Priority date: 2016-03-04
Filing date: 2017-01-05
Publication date: 2017-09-08

Abstract

Aspects of the present disclosure relate to computer based compact optical measuring system for obtaining various optical properties including optical rotation, magnitude of optical rotation, optical absorption and transmittance of optically active organic and inorganic substances at several wavelengths, in which the need for electro optic modulation or magneto optic modulation is obviated. The disclosed system can be configured to accomplish non- destructive method of measuring both rotatory polarization and optical absorption (or transmittance) of chemical substances at several wavelengths. The disclosed system can be used as a spectropolarimeter as well as spectrophotometer by providing simple modifications to the components thereof.

Description

SYSTEM FOR MEASURING OPTICAL PARAMETERS OF MATERIALS

FIELD OF THE I VENTION

[0001] The present disclosure pertains to system and methods for the measuring optical properties of the materials. In particular, the present disclosure pertains to an optical measuring system capable of measuring various optical properties such as, optical rotation, optical absorption and transmittance of organic and inorganic substances.

BACKGROUND OF THE INVENTION

[0002] Background description includes information that may be useful in understanding the present invention. It is not an admission that any of the information provided herein is prior art or relevant to the presently claimed invention, or that any publication specifically or implicitly referenced is prior art.

[0003] There have been various spectropolarimeters developed in the past, and many of these have been based on a common physical principle that, when plane-polarized light is passed through a substance or material, the plane of polarization of the light is rotated. Optically active substances (e.g. sucrose, camphor, etc.) have the ability to rotate plane-polarized light as it passes through the substance. That is, these substances rotate the orientation of polarized light about the axis of propagation as the light passes through the substance. The amount of this rotation is related to the substance or material rotating the light, the concentration of the substance, and the path length of light through the substance. This type of analysis, however, typically involves either electro optic modulation or magneto optic modulation technique which is complicated and requires significantly more complex and costly hardware.

[0004] A variety of absorption spectrophotometers are also known in the art which are generally used to perform quantitative and qualitative analysis of a specimen by obtaining absorbance and transmittance data of a substance or material contained in the specimen. Typically, spectrophotometers are used to determine concentration of a specific chemical in a liquid sample. Clearly, a wide array of instruments has been developed in the art, but none are capable of obtaining both rotatory polarization and light absorption (or transmittance) of a material or substance. [0005] There is thus a need in the art for an optical measuring device that obviates the need for electro optic modulation or magneto optic modulation to obtain optical rotation of a substance. More particularly, there remains a need in the art for an optical measuring device that is capable of measuring various optical properties of a substance, including optical rotation, optical absorption and transmittance characteristics of a substance. There still remains a need in the art to provide a simple and efficient optical measuring device that overcomes inherent design limitations of the prior art devices.

[0006] The present invention satisfies the existing needs, as well as others, and generally overcomes the deficiencies found in the prior art.

OBJECTS OF THE INVENTION

[0007] It is an object of the present disclosure to provide an optical measuring system that can be configured to accomplish non-destructive method of measuring both rotatory polarization and optical absorption (or transmittance) of chemical substances.

[0008] It is a further object of the present disclosure to provide an optical measuring system that obviates the need for electro optic modulation or magneto optic modulation to measure optical rotation of chemical substances.

[0009] It is another object of the present disclosure to provide an optical measuring system for obtaining various optical properties including optical rotation, optical absorption and transmittance of optically active organic and inorganic substances at several wavelengths.

[00010] It is another object of the present disclosure to provide an optical measuring system that is capable of being used as a spectropolarimeter as well as spectrophotometer.

[00011] It is another object of the present disclosure to provide an optical measuring system that is compact, simple in construction, and inexpensive.

[00012] It is another object of the present disclosure to provide an optical measuring system that enables greater ease of application and achieving improved accuracy and precision in obtained results.

[00013] It is another object of the present disclosure to provide an optical measuring system that can simplify the analysis and implementing hardware to provide precise analysis of optical rotation, optical absorption and transmittance of organic and inorganic substances in real time.

[00014] It is another object of the present disclosure to provide an optical measuring system that exhibits high performance characteristics and high resolution capacity. [00015] It is another object of the present disclosure to provide a simple method to obtain various optical characteristics such as optical rotations, light absorption and transmittance data of optically active organic and inorganic substances.

SUMMARY OF THE INVENTION

[00016] Aspects of the present disclosure relate to computer based optical measuring system for obtaining various optical properties including optical rotation, optical absorption and transmittance of optically active organic and inorganic substances at several wavelengths. The disclosed system can be configured to accomplish non-destructive method of measuring both rotatory polarization and optical absorption (or transmittance) of chemical substances at several wavelengths. The disclosed system can be used as a spectropolarimeter as well as spectrophotometer by providing simple modifications to the components thereof

[00017] In an embodiment, the present disclosure provides a system for measuring optical parameters such as optical rotation and its magnitude of a sample material, wherein the system can include:

a light source configured to produce a beam of light covering a wide spectral band;

one or more collimating lens configured along an optical path of the beam of light to convert the beam of light into a beam of collimated light;

an optical means configured along the optical path to provide a parallel beam of light from the beam of collimated light;

an optical filter configured along the optical path;

a polarizer configured along the optical path for plane-polarizing the parallel beam of light;

a sample cell configured along the optical path and to hold a solution of a substance whose optical activity is to be measured;

a first beam splitter configured along the optical path to receive and split a beam of light emitted from the sample cell into a first and second beam, wherein the first beam is passed in its original path, and the second beam is reflected at an angle of 90 deg with respect to the first beam; a second beam splitter configured along the optical path to receive and split the first beam transmitted from the first beam splitter into a third and fourth beam, wherein the third beam is transmitted in a direction to its original path and the fourth beam is reflected at an angle of 90 deg with respect to the third beam;

a third beam splitter configured to receive and split the second beam reflected from the first beam splitter into a fifth and sixth beam, wherein the fifth beam is transmitted in a direction to its original path and the sixth beam is reflected at an angle of 90 deg with respect to the fifth beam;

first, second and third analyzer configured to receive, respectively, the third, fifth and sixth beam of light and to direct each of the beams through an optical element;

an optical element configured in the path of the fourth beam to receive the fourth beam reflected from the second beam splitter; and

a detector configured to measure the intensity of light emitted from each of the optical elements.

[00018] In another embodiment the present disclosure provides a system for measuring optical absorption (or transmittance) of a sample material, wherein the system can include:

an optical filter configured along the optical path;

a first sample cell configured along the optical path and to hold a blank solution;

a first beam splitter configured along the optical path to receive and split a beam of light emitted from the first sample cell into a first and second beam, wherein the first beam is transmitted in a direction to its original path and the second beam is reflected at an angle of 90 deg with respect to the first beam;

a second beam splitter configured along the optical path to receive and split the first beam transmitted from the first beam splitter into a third and fourth beam, wherein the third beam is transmitted in a direction to its original path and the fourth beam is reflected at an angle of 90 deg with respect to the third beam;

a second sample cell configured along the optical path and to hold a solution of a substance whose optical absorption or transmittance is to be measured, wherein the third beam from the second beam splitter passes through the second sample cell to an optical element;

first and second analyzer configured to receive, respectively, the fifth and sixth beam of light and to direct each of the beams through an optical element;

[00019] In an embodiment, the system for measuring optical parameters can further include an acquisition system that can be configured to collect polarization data from the detector. Further, the acquisition system can be controlled by a programmable computing device.

[00020] In an embodiment, the system for measuring optical parameters can further include a control module to control intensity of the beam of light emitted from the light source.

[00021] In another embodiment, the system for measuring optical parameters can further include a control module that can be configured to control the wavelength of beam of light leaving the optical filter. [00022] Various objects, features, aspects and advantages of the inventive subject matter will become more apparent from the following detailed description of preferred embodiments, along with the accompanying drawing figures in which like numerals represent like components.

BRIEF DESCRIPTION OF THE DRAWINGS

[00023] The accompanying drawings are included to provide a further understanding of the present disclosure, and are incorporated in and constitute a part of this specification. The drawings illustrate exemplary embodiments of the present disclosure and, together with the description, serve to explain the principles of the present disclosure.

[00024] FIG. 1 illustrates the general principle of optical activity.

[00025] FIG. 2 is a schematic view illustrating transmission of light through a polarizer and an analyzer in accordance with embodiments of the present disclosure.

[00026] FIG. 3 is a schematic view illustrating working principle of a spectropolarimeter in accordance with embodiments of the present disclosure.

[00027] FIG. 4 is a schematic view illustrating an exemplary structure of a spectropolarimeter in accordance with embodiments of the present disclosure.

[00028] FIG. 5 is an exemplary block diagram showing hardware arrangement for measuring spectrorotatory polarization in accordance with embodiments of the present disclosure.

[00029] FIG. 6 illustrates an example of a computer based spectropolarimeter setup in accordance with embodiments of the present disclosure.

[00030] FIG. 7 is a schematic view illustrating an exemplary structure of a spectrophotometer in accordance with embodiments of the present disclosure.

DETAILED DESCRD7TION OF THE INVENTION

[00031] The following is a detailed description of embodiments of the disclosure depicted in the accompanying drawings. The embodiments are in such detail as to clearly communicate the disclosure. However, the amount of detail offered is not intended to limit the anticipated variations of embodiments; on the contrary, the intention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the present disclosure as defined by the appended claims. [00032] Each of the appended claims defines a separate invention, which for infringement purposes is recognized as including equivalents to the various elements or limitations specified in the claims. Depending on the context, all references below to the "invention" may in some cases refer to certain specific embodiments only. In other cases it will be recognized that references to the "invention" will refer to subject matter recited in one or more, but not necessarily all, of the claims.

[00033] Unless the context requires otherwise, throughout the specification which follow, the word "comprise" and variations thereof, such as, "comprises" and "comprising" are to be construed in an open, inclusive sense that is as "including, but not limited to."

[00034] Reference throughout 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. Thus, the appearances of the phrases "in one embodiment" or "in an embodiment" in various places throughout this specification are not necessarily all referring to the same embodiment. Furthermore, the particular features, structures, or characteristics may be combined in any suitable manner in one or more embodiments.

[00035] As used in this specification and the appended claims, the singular forms "a," "an," and "the" include plural referents unless the content clearly dictates otherwise. It should also be noted that the term "or" is generally employed in its sense including "and/or" unless the content clearly dictates otherwise.

[00036] In some embodiments, the numbers expressing quantities of ingredients, properties such as concentration, reaction conditions, and so forth, used to describe and claim certain embodiments of the invention are to be understood as being modified in some instances by the term "about." Accordingly, in some embodiments, the numerical parameters set forth in the written description are approximations that can vary depending upon the desired properties sought to be obtained by a particular embodiment. In some embodiments, the numerical parameters should be construed in light of the number of reported significant digits and by applying ordinary rounding techniques.

[00037] Notwithstanding that the numerical ranges and parameters setting forth the broad scope of some embodiments of the invention are approximations, the numerical values set forth in the specific examples are reported as precisely as practicable. The recitation of ranges of values herein is merely intended to serve as a shorthand method of referring individually to each separate value falling within the range. Unless otherwise indicated herein, each individual value is incorporated into the specification as if it were individually recited herein. All methods described herein can be performed in any suitable order unless otherwise indicated herein or otherwise clearly contradicted by context. The use of any and all examples, or exemplary language (e.g. "such as") provided with respect to certain embodiments herein is intended merely to better illuminate the invention and does not pose a limitation on the scope of the invention otherwise claimed. No language in the specification should be construed as indicating any non- claimed element essential to the practice of the invention.

[00038] The headings and abstract of the invention provided herein are for convenience only and do not interpret the scope or meaning of the embodiments.

[00039] The following discussion provides many example embodiments of the inventive subject matter. Although each embodiment represents a single combination of inventive elements, the inventive subject matter is considered to include all possible combinations of the disclosed elements. Thus if one embodiment comprises elements A, B, and C, and a second embodiment comprises elements B and D, then the inventive subject matter is also considered to include other remaining combinations of A, B, C, or D, even if not explicitly disclosed.

[00040] Various terms as used herein are shown below. To the extent a term used in a claim is not defined below, it should be given the broadest definition persons in the pertinent art have given that term as reflected in printed publications and issued patents at the time of filing.

[00041] Aspects of the present disclosure relate to computer based compact optical measuring system for obtaining various optical properties including optical rotation, magnitude of optical rotation, optical absorption and transmittance of optically active organic and inorganic substances at several wavelengths, in which the need for electro optic modulation or magneto optic modulation is obviated. The disclosed system can be configured to accomplish nondestructive method of measuring both rotatory polarization and optical absorption (or transmittance) of chemical substances at several wavelengths. The disclosed system can be used as a spectropolarimeter as well as spectrophotometer by providing simple modifications to the components thereof. FIG. 1 schematically illustrates the general principle of optical activity on which the solution according to the present disclosure is based.

[00042] In an embodiment, the present disclosure provides a system for measuring optical parameters such as optical rotation and its magnitude of a sample material, wherein the system can include:

a light source configured to produce a beam of light covering a wide spectral band; one or more collimating lens configured along an optical path of the beam of light to convert the beam of light into a beam of collimated light;

an optical filter configured along the optical path;

a first beam splitter configured along the optical path to receive and split a beam of light emitted from the sample cell into a first and second beam, wherein the first beam is passed in its original path, and the second beam is reflected at an angle of 90 deg with respect to the first beam;

a detector configured to measure the intensity of light emitted from each of the optical elements. [00043] In an embodiment, the system for measuring optical parameters can further include an acquisition system that can be configured to collect polarization data from the detector. Further, the acquisition system can be controlled by a programmable computing device.

[00044] In an embodiment, the system for measuring optical parameters can further include a control module to control intensity of the beam of light emitted from the light source.

[00045] In another embodiment, the system for measuring optical parameters can further include a control module that can be configured to control the wavelength of beam of light leaving the optical filter.

[00046] In an embodiment, the optical filter that can be used to construct the optical measuring system can be a linear interference filter which can pass wavelengths ranging from about 400 nm to about 700. The polarizer used to plane-polarize an incident light can be a thin film polarizer, and the optical element can be a spherical lens.

[00047] According to embodiments, the first, second and third beam splitters of the system can be non-polarizing beam splitters, preferably a 50:50 non-polarizing beam splitter.

[00048] Referring to FIGs. 2 and 3 that schematically illustrate working principle of the present optical measuring system configured to measure optical rotation and its magnitude of a sample chemical substance in accordance with embodiments of the present disclosure. As shown in FIG. 2, a polarizer (P) and an analyzer (A) can be arranged on a common axis so that their transmission (TA) axes can be parallel. An unpolarized light from a monochromator can be allowed to fall on the polarizer (A). The beam of light emerging from the polarizer can be a linearly polarized light and its intensity Ii can be equal to half the intensity of the incident unpolarized light. A plane polarized light Ii can then pass through the analyzer (A) without any obstruction as the transmission axis of the analyzer is parallel to the plane polarized light. Intensity of beam of light leaving the analyzer can be I = Ii.

[00049] As shown in FIG. 3, an optically active substance can be placed between a polarizer (P) and an analyzer (A). Optically active substance can rotate the plane of vibration of linearly polarized beam, and a rotation of the polarized light caused by the substance can be Θ. The intensity of beam of light leaving the analyzer can be I = Ii cos²0 (eq.1.0), where "Ii" can be intensity of beam before falling on the analyzer, "I" can be intensity after the analyzer, and Θ can be angle of rotation of plane polarized light made with transmission axes. The magnitude of optical rotation Θ can be obtained by substituting the values for "Ii" and "I" into the above equation. [00050] FIG. 4 schematically illustrates preferred configuration of an optical measuring system configured (as a spectropolarimeter) for measuring optical rotation and its magnitude of a test substance in accordance with embodiments of the present disclosure. As shown in FIG. 4, the spectropolarimeter system can include a narrow aperture slit 104 that can be illuminated by a light source 102 (e.g. xenon lamp) that can be of 24V, 100W. A set of collimating lens 50 and 52 can be positioned at a distance equal to its focal length from the slit 104 which can send out a collimated beam of light. The collimating lens can be a pair of piano convex lens that can be opposite to each other. A narrow aperture silt 106 can be illuminated by the collimated beam of light and an optical element 54 (e.g. spherical lens) can be situated at a distance equal to its focal length from the slit 106 which sends out a parallel white light beam long distance. The parallel white light beam can then be allowed to fall on a linear variable interference filter 108 having a wavelength ranging from 400 nm to 700 nm. Using a wavelength selector one particular wavelength can be selected. The filtered beam of unpolarized light having a particular wavelength can then be allowed to fall on a polarizer 110 which in turn can linearly polarize the incident beam. The resulting plane polarized beam can then be allowed to pass through a sample cell 112 which can contain a solution of an optical active substance.

[00051] After the sample tube, a first beam splitter 200 can be configured along the optical path such that it reflects 50% of the incident light beam at 90° angle and allows 50% of light beam in a straight path. The beam of light travels in a straight path can then be allowed to fall on a second beam splitter 202 which in turn can reflect 50% of the incident light at 90° angle and allow another 50% in a straight path. The light beam which is reflected 90° at the second beam splitter 202 can be allowed to fall on a photo detector 406 through a spherical lens 62. The beam of light which leaves the beam splitter 202 and travels in a straight path can be allowed to fall on the analyzer 300 which can be configured parallel to the polarizer 110. A spherical lens 56 and a photo detector 400 can be configured along the optical path to measure the intensity of the beam of light leaving the analyzer 300. Similarly, the beam of light reflected at 90° angle at the beam splitter 200 can be allowed to fall on a beam splitter 204. The beam splitter 204 can allow 50% of the beam travelling in a straight path to fall on the analyzer 302 which can be fixed at right 45°. After the analyzer 302, a spherical lens 58 and a photo detector 402 can be configured along the optical path to measure intensity of the light leaving the polarizer 204. The light beam reflected 90° at the beam splitter 204 can be allowed to fall on the analyzer 304 which can be fixed at left 45°. After the analyzer 304, a spherical lens 60 and a photo detector 404 can be configured along the optical path to measure intensity of the beam of light leaving the polarizer 304. Thus, the beam of light leaving the sample cell 112 can be divided into six different beams of approximately equal intensity.

[00052] According to embodiments of the present disclosure, 50:50 non-polarizing beam splitter plates can be used as beam splitters (200, 202 and 204) to construct the spectropolarimeter. These beam splitters can provide 50/50 splitting ratio that is nearly independent of polarization of an incident light.

[00053] FIG. 5 schematically illustrates hardware arrangement for measuring spectrorotatory polarization of a test sample. All the photo detectors (400, 402, 404 and 406) can be connected to a data acquisition module 500 after conditioning. The data acquisition module 500 can be configured to collect polarization data from the photo detectors. The light source 102 can be controlled by an automatic intensity control circuit through a D/A port of data acquisition module 500. The optical filter 108 can be configured with the data acquisition module 500 which can control the wavelength of beam of light leaving the optical filter 108. The data acquisition module 500 can be controlled by a programmable computing device, and the sign of optical rotation and magnitude of optical rotation can be displayed on monitor of the computing device.

[00054] FIG. 6 illustrates an example of a computer based spectropolarimeter setup in accordance with embodiments of the present disclosure. As shown in FIG. 6, the spectropolarimeter can have a platform that can be rectangular, and the internal portion of the instrument blacking (painted) can be configured to absorb internal reflections of a light. The beam splitters and the analyzers can be configured such that any change in a light intensity equally appears for all six divided beams.

[00055] In an embodiment, the distance between the beam splitters (200, 202 and 204), analyzers (300, 302 and 304) and detector (406) can preferably be beam splitter(200).beam splitter(202)=beam splitter(200).beam splitter(204)=beam splitter(202).detector(406)=beam splitter(202).analyzer(300)=beam splitter(204).analyzer(302)= beam splitter(204).analyzer(304).

[00056] In an embodiment, magnitude of optical rotation Ιθΐ of a chemical substance can be obtained by passing an unpolarized light of specific wavelength through a sample cell 112 that contains a solution of a substance whose optical activity/optical rotation is to be measured. Wavelength of the unpolarized light can be selected by a wavelength selector from the variable filter. The intensity of the light I can be measured after the analyzer Al by the photo detector Dl. The value of Ιθ ΐ can be calculated from the relation I = Ii cos20 without measuring Ii. Ii can be kept as a preset and a predetermined value.

[00057] A beam of light leaving the sample cell 112 can be divided into two equal parts by the beam splitter 200. One part can be directed to pass in a straight direction, and the other part can be diverted 90° and further directed to the beam splitter 204. One part from 204 can be allowed to pass in a straight direction through the analyzer 302, spherical lens 58 and the photo detector 402. The other part from 204 can be allowed to pass at an angle of 90° through the analyzer 304, spherical lens 60 and the photo detector 404. The straight part from 200 can be further divided into two equal parts using 202, wherein one part can be directed to pass in straight direction through the analyzer 300, spherical lens 56 and the photo detector 400, and the other part from 202 can be directed to pass at an angle of 90° through the spherical lens 62 and the photo detector 406. A computing device can be employed to continuously monitor the light intensity at photo detector 406 and to keep the intensity of light constant irrespective of type of solution employed and its concentration. As the light after the beam splitter 202 can divide into two equal parts, and also can follow the same optical paths, the intensity of the light at 406 can be equal to Ii before the analyzer 300, i.e. Ii can always be fixed and can be a known value, and hence only I may be measured.

[00058] In an embodiment, positions of the components such as beam splitters, analyzers and detector after the sample cell 112 can be chosen to be beam splitter(200).beam splitter(202)=beam splitter(200).beam splitter(204)=beam splitter(202).detector(406)=beam splitter(202).analyzer(300)=beam splitter(204).analyzer(302)= beam splitter(204).analyzer(304). This can prevent any error during the spectropolarimetric or spectrophotometric analysis when the intensity of light source is regulated by the computing device to make the intensity at detector 406 (in turn Ii) constant.

[00059] In an embodiment, sign of optical rotation Θ of a sample can be measured by fixing the position of analyzer 302 at 45° in clockwise direction and fixing analyzer 304 at 45° in anticlockwise direction with respect to polarizer 110 in absence of sample cell.

[00060] As described above, a beam of light leaving the sample cell 112 can be divided into two equal parts by the beam splitter 200. One part can be diverted at an angle of 90° and allowed to pass through beam splitter 204. At 204, one part can be allowed to pass through the analyzer 302 which is fixed at clockwise 45° and through the photo detector 402. The other part can be diverted at 90° from 204 and the then the diverted beam can be allowed to pass through the analyzer 304 which is fixed anticlockwise at 45° and through the photo detector 404. The intensities of the light after the analyzer 302 and 304 can be measured and compared. Due to the arrangement of the analyzers 302 and 304 in clockwise and anticlockwise directions by 45°, all the dextro rotations and the intensities measured at analyzer 302 can be greater than the intensities measured at analyzer 304.

[00061] For example, if a light rotated by 30° in clockwise (dextro) direction falls on the analyzers 302 and 304, it can make an effective angle of 45-30=15° since 302 is already placed at 45 ⁰ in clockwise direction and the light can make an effective angle of 45 + 30=75 °, since analyzer 304 is already placed at 45° in anticlockwise direction. Thus, the intensity of the light after analyzer 302 can be more than the intensity of the light after analyzer 304. This can be true for all dextro rotations. Similarly, if a light rotated by 30° in anticlockwise (laevo) direction falls on the analyzers 302 and 304, it can make an effective angle of 45+30 =75° at analyzer 302 and an effective angle of 45-30=15° at analyzer 304. Thus, the intensity of the light after analyzer 302 can be lesser than the intensity of the light after analyzer 304. This can be true for all laevo rotations. The measurement data can be processed by a computing device, and the magnitude and sign of the optical rotation can be displayed on the display thereof.

[00062] In an embodiment, optical rotation (both magnitude Ιθΐ and sign of optical rotation) can be measured for a same sample for different wavelengths which can be selected by the wavelength selector from the variable filter 108. The wavelength can preferably be selected from 400 nm to 700 nm. Optical rotator dispersion curve of a sample can be obtained by generating a graph by a computer by plotting optical rotation Vs wave length.

[00063] In another embodiment, the optical measuring system of the present disclosure can also be used to measure absorbance and transmittance of a substance by simply modifying the arrangement of the components of the spectropolarimeter. FIG. 7 schematically illustrates an exemplary arrangement for measuring light absorption (or transmittance) of a substance. As shown in FIG. 7, a second sample cell 114 can be placed between the beam splitter 202 and the spherical lens 56. The second sample cell can have 10 mm thickness. The first sample cell 112 can be filled with blank sample to avoid divergence of polarized light. A computing device can be employed to continuously monitor the light intensity at detector 406 and keep the same constant irrespective of the sample cell 112. The intensity (Jo) of light at detector 400 can be measured for the blank sample and recorded, and then a test sample can be placed before the optical detector 400 and the intensity (I) of 400 can be measured. The transmittance and absorption of the test sample can be calculated using the following equation.

T = f (eq.1.1)

A = log₁₀ i (eq.1.2)

or

Α = 1ο_§10 ^ (eq.1.3)

[00064] In another aspect the present disclosure provides a system for measuring optical parameters such as optical absorption or transmittance of a sample material, wherein the system can include:

an optical filter configured along the optical path;

a second sample cell configured along the optical path and to hold a solution of a substance whose optical absorption or transmittance is to be measured, wherein the third beam from the second beam splitter passes through the second sample cell to an optical element; a third beam splitter configured to receive and split the second beam reflected from the first beam splitter into a fifth and sixth beam, wherein the fifth beam is transmitted in a direction to its original path and the sixth beam is reflected at an angle of 90 deg with respect to the fifth beam;

[00065] In spectropolarimeter point of view, the intensity Ii can be kept constant by adjusting the intensity of light source after selecting the wavelength every time. Thus, the process can compensate the intensity loss through a solution due to beer's and lambert's law irrespective of type and concentration of a solution. The intensity Ii at every wavelength can be maintained constant. In spectrophotometer point of view, the intensity of light at detector 406 can be maintained constant for every selected wavelength after passing through the sample cell 112 (blank sample) while doing spectrophotometeric measurement. The second sample holder 114 can be kept just before the detector 400 and the intensities can be measured. The transmittance and absorption data can be obtained from the detector 400.

ADVANTAGES OF THE PRESENT INVENTION

[00066] The present disclosure provides a compact optical measuring system that can be configured to accomplish non-destructive method of measuring both rotatory polarization and light absorption (or transmittance) of chemical substances.

[00067] The present disclosure provides an optical measuring system in which the need for electro optic modulation or magneto optic modulation to measure optical rotation of chemical substances has been obviated. [00068] The present disclosure provides an optical measuring system that is capable of measuring both rotatory polarization and light absorption (or transmittance) of chemical substances.

[00069] The present disclosure provides an optical measuring system that simplifies the analysis and implementing hardware to provide precise analysis of optical rotation, optical absorption and transmittance of organic and inorganic substances in real time.

[00070] The present disclosure provides an optical measuring system that is small in size, simple in construction, and inexpensive.

[00071] The present disclosure provides an optical measuring system that exhibits high performance characteristics and high resolution capacity.

[00072] The present disclosure provides an improved optical measuring system that enables greater ease of application and achieving improved accuracy and precision in obtained results.

[00073] The present disclosure provides an optical measuring system for obtaining various optical properties including optical rotation, concentration studies optical absorption and transmittance of optically active organic and inorganic substances at several wavelengths.

[00074] The present disclosure provides an optical measuring system that is simple in construction and inexpensive than prior art devices, and the operation would not require highly skilled users to utilize the device.

[00075] The present disclosure provides an optical measuring system that is small in size and is easily transportable.

[00076] The present disclosure provides an optical measuring system that overcomes the drawbacks associated with the prior art devices.

Claims

We Claim:

1. A system for measuring optical parameters of a sample material, comprising:

one or more collimating lens configured along an optical path of said beam of light is converted into a beam of collimated light;

an optical means configured along the optical path to provide a parallel beam of light from said beam of collimated light;

an optical filter configured along the optical path;

a polarizer configured along the optical path for plane-polarizing said parallel beam of light;

a first beam splitter configured along the optical path to receive and split a beam of light emitted from said sample cell into a first and second beam, wherein said first beam is passed in its original path, and said second beam is reflected at an ang le of 90° with respect to said first beam.

a second beam splitter configured along the optical path to receive and split said first beam transmitted from said first beam splitter into a third and fourth beam, wherein said third beam is transmitted in a direction of its original path and said fourth beam is reflected at an angle of 90 deg with respect to said third beam;

a third beam splitter configured to receive and split said second beam reflected from said first beam splitter into a fifth and sixth beam, wherein said fifth beam is transmitted in a direction to its original path and said sixth beam is reflected at an angle of 90 deg with respect to said fifth beam;

first, second and third analyzer configured to receive, respectively, said third, fifth and sixth beam of light and to direct each of said beams through an optical element; an optical element configured in the path of said fourth beam to receive the said fourth beam reflected from the said second beam splitter; and

a detector configured to measure intensity of light transmitted from each of said optical elements.

2. The system according to claim 1, further comprising an acquisition system configured to collect polarization data from the said detector.

3. The system according to claim 2, wherein said acquisition system is configured with a programmable computing device.

4. The system according to claim 1, further comprising a control module to control intensity of said beam of light from the said light source.

5. The system according to claim 1, further comprising a control module configured to control the wavelength of beam of light leaving said optical filter.

6. The system according to claiml, wherein said sample material is an optically active organic or inorganic chemical.

7. The system according to claim 1, wherein said optical filter is a linear variable interference filter.

8. The system according to claim 7, wherein said interference filter passing wavelengths from about 400 nm to about 700.

9. The system according to claim 1, wherein said polarizer is a thin film polarizer.

10. The system according to claim 1, wherein said first, second and third beam splitters are selected from non-polarizing beam splitters.

11. The system according to claim 1, wherein said first, second and third beam splitters comprise 50:50 non-polarizing beam splitter.

12. The system according to claim 1, wherein said optical element is a spherical lens.

13. The system according to claim 1, wherein said system is used for measuring optical parameters selected from optical rotation, magnitude of optical rotation and direction of rotation.

14. A system for measuring optical parameters of a sample material, comprising:

one or more collimating lens configured along an optical path of said beam of light to convert said beam of light into a beam of collimated light;

an optical filter configured along the optical path;

a first beam splitter configured along the optical path to receive and split a beam of light emitted from said first sample cell into a first and second beam, wherein said first beam is transmitted in a direction to its original path and said second beam is reflected at an angle of 90 deg with respect to said first beam;

a second beam splitter configured along the optical path to receive and split said first beam transmitted from said first beam splitter into a third and fourth beam, wherein said third beam is transmitted in a direction to its original path and said fourth beam is reflected at an angle of 90 deg with respect to said third beam;

a second sample cell configured along the optical path and to hold a solution of a substance whose optical absorption or transmittance is to be measured, wherein said third beam from said second beam splitter passes through said second sample cell to an optical element; a third beam splitter configured to receive and split said second beam reflected from said first beam splitter into a fifth and sixth beam, wherein said fifth beam is transmitted in a direction to its original path and said sixth beam is reflected at an angle of 90 deg with respect to said fifth beam;

first and second analyzer configured to receive, respectively, said fifth and sixth beam of light and to direct each of said beams through an optical element;

an optical element configured in the path of said fourth beam to receive said fourth beam reflected from said second beam splitter; and

a detector configured to measure intensity of light emitted from each of said optical element.

15. The system according to claim 14, wherein said system is used for measuring optical parameters selected from optical absorption and optical transmittance.