Fourier transform spectrometer based on an array of coherent light sources

Abstract

The present application relates to a kind of Fourier transform spectrometer based on coherent light source array, comprising: light source, light transmission device, control circuit, detector, amplifier circuit and computer, the control circuit is electrically connected with the light transmission device, for controlling the on-off of light in the light transmission device;The amplifier circuit is connected with the detector, for recording and amplifying the photoelectric signal obtained by the detector;The computer is connected with the amplifier circuit, and the computer is installed with spectral analysis software, for Fourier transform, the Fourier transform spectrometer based on coherent light source array further includes a coherent light source array, the beginning of the light transmission device is fixed on the light source, and the terminal is fixed on the coherent light source array, and the light transmission device is used to transmit the light emitted by light source to the coherent light source array.

Description

Technical Field

[0001] This invention belongs to the field of spectral analysis technology and relates to a Fourier transform spectrometer, in which the interferometer and light source are replaced by a surface array composed of a coherent light source. Background Technology

[0002] A Fourier transform spectrometer (FTR spectrometer) mainly consists of a light source, aperture, beam splitter, fixed mirror, a precisely controlled moving mirror, sample chamber, detector, various mirrors, control circuit boards, and amplification circuits. The core component of the Fourier transform spectrometer is the interferometer, which mainly consists of a fixed mirror, a moving mirror, and mechanical components that precisely control the movement of the moving mirror. The movement of the moving mirror causes the optical path difference between the moving and fixed mirrors to change continuously. When the optical path difference is 0, the interference intensity is the maximum. The movement of the moving mirror causes the signal received by the detector to change continuously with the optical path difference, thus obtaining the interferogram. The final spectrum can be obtained by Fourier transforming the interferogram.

[0003] Existing Fourier transform spectrometers primarily rely on mechanical components to alter the optical path difference between the moving and fixed mirrors for measurement. The presence of these mechanical components makes the spectrometers relatively large, limiting their portability and thus limiting their use to laboratory settings. Furthermore, the mechanical components can cause signal fluctuations during operation, affecting the repeatability and accuracy of the tests. Therefore, to prevent signal fluctuations caused by these mechanical components, the interferometers in existing Fourier transform spectrometers are often designed with high precision to ensure accurate movement of the moving mirror and that it remains parallel to the fixed mirror throughout its movement, resulting in a very high price for these spectrometers. In addition, the light emitted from the light source passes through several mirrors before entering the interferometer, further increasing the spectrometer's size and cost.

[0004] Therefore, designing a small and low-cost Fourier transform spectrometer would be of great significance. Summary of the Invention

[0005] In view of this, it is indeed necessary to design a smaller and less expensive Fourier transform spectrometer.

[0006] A Fourier transform spectrometer based on a coherent light source array includes: a light source, a light transmission device, a control circuit, a detector, an amplification circuit, and a computer. The control circuit is electrically connected to the light transmission device and is used to control the on / off state of light in the light transmission device. The detector is used to detect the photoelectric signal after the light beam passes through the sample. The amplification circuit is connected to the detector and is used to record and amplify the photoelectric signal obtained by the detector. The computer is connected to the amplification circuit and has spectral analysis software installed in it for performing Fourier transforms. The spectrometer further includes a coherent light source array. The starting end of the light transmission device is fixed to the light source, and the ending end is fixed to the coherent light source array. The light transmission device is used to transmit the light emitted by the light source to the coherent light source array.

[0007] A Fourier transform spectrometer based on a coherent light source array comprises a light source, a light transmission device, a control circuit, a coherent light source array, a detector, an amplification circuit, and a computer. The control circuit is electrically connected to the light transmission device and is used to control the on / off state of light in the light transmission device. The starting end of the light transmission device is fixed to the light source, and the ending end is fixed to the coherent light source array. The light transmission device is used to transmit light emitted from the light source to the coherent light source array. The detector is used to detect the photoelectric signal of the light beam generated by the coherent light source array after passing through the sample. The amplification circuit is connected to the detector and is used to record and amplify the photoelectric signal obtained by the detector. The computer is connected to the amplification circuit and has spectral analysis software installed on it for performing Fourier transforms.

[0008] The coherent light source array is a single coherent light source array, and the multiple light source pixels are located on the same surface of the coherent light source array.

[0009] Compared to existing technologies, the Fourier transform spectrometer based on a coherent light source array provided by this invention replaces the interferometer and light source with a coherent light source array. This directly reduces the mechanical components in the interferometer and the increased volume of the reflectors between the light source and the interferometer, effectively reducing the size of the Fourier transform spectrometer and significantly lowering the cost of the Fourier transform infrared spectrometer, making it more portable. This invention uses circuit control of the coherent light source array, avoiding the signal fluctuations caused by the mechanical components of the interferometer that lead to a decrease in the repeatability of test results, ultimately improving the stability of the Fourier transform spectrometer. Furthermore, the precision of the planar coherent light source array in this invention is reduced by one dimension compared to the three-dimensional structure of the interferometer, further reducing its size. Attached Figure Description

[0010] Figure 1 This is a schematic diagram of a Fourier transform spectrometer based on a coherent light source array, provided as an embodiment of the present invention.

[0011] Figure 2 The image shows the emission status of the coherent light source array of the Fourier transform spectrometer provided in this embodiment of the invention at a certain moment.

[0012] Explanation of main component symbols

[0013] Fourier transform spectrometer 100

[0014] Light source 10

[0015] Light transmission device 20

[0016] Control circuit 30

[0017] Coherent light source array 40

[0018] Substrate 402

[0019] 404 pixels of light source

[0020] Detector 50

[0021] Amplifier circuit 60

[0022] Computer 70

[0023] The following detailed description, in conjunction with the accompanying drawings, will further illustrate the present invention. Detailed Implementation

[0024] The embodiments of this technical solution will be further described in detail below with reference to the accompanying drawings and specific examples.

[0025] Please see Figure 1 This invention provides a Fourier transform spectrometer 100 based on a coherent light source array (hereinafter referred to as Fourier transform spectrometer 100). The Fourier transform spectrometer 100 includes a light source 10, a light transmission device 20, a control circuit 30, a coherent light source array 40, a detector 50, an amplifier circuit 60, and a computer 70.

[0026] The light source 10 is preferably, but not limited to, a laser. In this embodiment, the light source 10 is an infrared laser. Of course, the light source 10 is not limited to the infrared laser in this embodiment, and can also be a laser of other wavelengths.

[0027] The starting end of the light transmission device 20 is fixed to the light source 10, and the ending end is fixed to the coherent light source array 40. The light transmission device 20 is used to transmit the light emitted by the light source 10 to the coherent light source array 40. In this embodiment, the light transmission device 20 is an optical fiber.

[0028] The control circuit 30 is electrically connected to the light transmission device 20 and is used to precisely control the on / off state of light in the light transmission device 20. The control circuit 30 can be further designed as a control circuit board.

[0029] The coherent light source array 40 includes a substrate 402 and a plurality of light source pixels 404. The plurality of light source pixels 404 are disposed on the substrate 402. The plurality of light source pixels 404 are disposed on the same surface or on two opposite surfaces of the substrate 402. The plurality of light source pixels 404 are coherent light source pixels. The number, spacing, and arrangement of the plurality of light source pixels 404 can be designed according to actual needs. In this embodiment, the coherent light source array 40 is a one-sided coherent light source array, and the plurality of light source pixels are located on the same surface of the coherent light source array 40 and arranged in a matrix shape on the surface of the substrate 402.

[0030] The substrate 402 is used to fix the plurality of light source pixels 404. In some embodiments, the substrate 402 is a transparent substrate, such as a PET substrate, a PI substrate, a PMMA substrate, or quartz glass. In other embodiments, the substrate 402 is an opaque mesh. Of course, the substrate 402 is not limited to the above embodiments, as long as it can fix the plurality of light source pixels 404.

[0031] The distribution shape of the light source pixels 404 is not limited and can be rectangular, circular, rhomboid, etc. In this embodiment, the light source pixels 404 are distributed in a circle, and the distance from each point on the circumference to the center of the test area is the same, which makes the control circuit of the light source pixels 404 easier to design.

[0032] The on / off state of the light source at each pixel in the coherent light source array 40 at different times can be controlled by a precisely designed program, thereby obtaining light beams with different optical path lengths, where the optical path length is the distance from different light source pixels to the sample center. For example, in some embodiments, the light source at each pixel in the coherent light source array 40 is addressed and its distance from the sample center is recorded and marked. Light source pixels with the same distance from the sample center are grouped together. Preferably, the distances from adjacent groups of light source pixels to the sample center form an arithmetic sequence, analogous to the movement of a moving mirror in an interferometer. The illumination time of adjacent groups of light source pixels is also preferably an arithmetic sequence. In this way, light beams with different optical path differences can be obtained, where the optical path difference is the difference between the distances from different light source pixels to the sample center. It is understood that the method of controlling the on / off state of the light source at each pixel in the coherent light source array 40 at different times through a precisely designed program is not limited to the embodiments described above, and other programs can be designed for control depending on the implementation. On the plane of the coherent light source array 40, the light source pixels are grouped according to an arithmetic progression based on their optical path length. The optical path difference between different groups of light source pixels is designed to be a multiple of a small optical path difference. This is analogous to the movement of the moving mirror in a Fourier transform infrared spectrometer, which causes a series of optical path differences between the two beams of light generated in the interferometer. Preferably, the small optical path difference is greater than 0 mm and less than or equal to 2 mm; for example, the small optical path difference can be 2 mm, 1 mm, etc. Similarly, the design of the optical path difference is not limited to the above method and can be designed according to specific conditions. Please refer to [link / reference]. Figure 2 In the coherent light source array 40, solid dots represent a group of light source pixels illuminated at a given moment. At the next moment, another group of light source pixels will be illuminated, and so on, resulting in multiple light beams with different optical path differences. The light beams formed by different groups of light source pixels striking the sample allow the light intensity to continuously change with the optical path difference. By using circuit control to control the coherent light source array 40, signal fluctuations caused by the mechanical components of the interferometer in existing Fourier transform spectrometers are avoided, thus preventing a decrease in the repeatability of test results and ultimately improving the stability of the Fourier transform spectrometer.

[0033] The detector 50 is used to detect the light intensity of light beams with different optical path differences after passing through the sample, thereby obtaining an interferogram. The detector 50 can be a commonly used detector in existing Fourier transform spectrometers, such as triglycanium sulfate (TGS), barium strontium niobate, mercury cadmium telluride, indium antimonide, indium gallium arsenide, etc.

[0034] The amplification circuit 60 is connected to the detector 50 and is used to record and amplify the photoelectric signal obtained by the detector 50. The amplification circuit 60 can be further designed as an amplification circuit board.

[0035] The computer 70 is connected to the amplifier circuit 60. The computer 70 is equipped with spectral analysis software. The interferogram is subjected to Fourier transform using this software, directly transforming the interference signal image to obtain the sample's spectrum. The model of the computer 70 is not limited, as long as it can install spectral analysis software capable of performing Fourier transforms.

[0036] When the Fourier transform spectrometer 100 is used, the light source 10 emits a laser beam, which is transmitted to the coherent light source array 40 through the light transmission device 20. By controlling the on and off of the light source at each pixel at different times, multiple beams with different optical path differences are generated. After passing through the sample, these multiple beams hit the detector 50. The detector 50 detects the light intensity of the beams with different optical path differences after passing through the sample, thereby obtaining an interference pattern. The interference pattern is recorded and amplified by the amplification circuit 60 and then transmitted to the computer 70. Finally, the spectral software on the computer 70 performs a Fourier transform on the interference pattern to obtain the spectrum of the sample.

[0037] Depending on the wavelength of the light beam emitted by the light source 10, the Fourier transform spectrometer 100 can obtain the spectrum of the sample in different wavelength bands. In this embodiment, the laser beam is an infrared laser beam, and the Fourier transform spectrometer 100 obtains the infrared spectrum of the sample.

[0038] The Fourier transform spectrometer based on a coherent light source array provided by this invention replaces the interferometer and light source with a coherent light source array on the same plane. This directly reduces the volume added by the mechanical components in the interferometer and the reflectors between the light source and the interferometer, effectively reducing the size of the Fourier transform spectrometer. This invention uses circuit control of the planar coherent light source array to avoid signal fluctuations caused by the mechanical components of the interferometer, which leads to a decrease in the repeatability of test results and ultimately improves the stability of the Fourier transform spectrometer. The core component of existing Fourier transform spectrometers is the interferometer, which is manufactured with great precision and requires high precision in three-dimensional space, making Fourier transform spectrometers very expensive and limiting their applications. The planar coherent light source array of this invention reduces the precision by one dimension compared to the three-dimensional structure of the interferometer. Furthermore, using circuits to control the on / off of the optical path is more operable and repeatable than using circuits to achieve precise movement of mechanical components, thus improving system stability. The use of a planar coherent array light source in this invention can greatly reduce the cost of the Fourier transform spectrometer, making it more portable.

[0039] Furthermore, those skilled in the art may make other changes within the spirit of this invention. Of course, all such changes made in accordance with the spirit of this invention should be included within the scope of protection claimed by this invention.

Claims

1. A Fourier transform spectrometer based on a coherent light source array, comprising: The system comprises a light source, a light transmission device, a control circuit, a detector, an amplification circuit, and a computer. The control circuit is electrically connected to the light transmission device and is used to control the on / off state of light in the light transmission device. The detector is used to detect the photoelectric signal after the light beam passes through the sample. The amplification circuit is connected to the detector and is used to record and amplify the photoelectric signal obtained by the detector. The computer is connected to the amplification circuit and is equipped with spectral analysis software for performing Fourier transforms. The system is further characterized by including a coherent light source array. The starting end of the light transmission device is fixed to the light source, and the ending end is fixed to the coherent light source array. The light transmission device is used to transmit light emitted from the light source to the coherent light source array. The coherent light source array includes a substrate and multiple light source pixels, which are disposed on the substrate. The on / off state of the light source at each pixel in the coherent light source array at different times is controlled by a program to obtain light beams with different optical paths, which are the distances from different light source pixels to the center of the sample.

2. The Fourier transform spectrometer based on a coherent light source array as described in claim 1, characterized in that, The coherent light source array is a single coherent light source array, and the multiple light source pixels are located on the same surface of the coherent light source array.

3. The Fourier transform spectrometer based on a coherent light source array as described in claim 1, characterized in that, On the plane of the coherent light source array, the light source pixels are grouped according to different optical path differences, and the optical path difference formed between different groups of light source pixels is designed to be a multiple of a small optical path difference.

4. The Fourier transform spectrometer based on a coherent light source array as described in claim 1, characterized in that, In the coherent light source array, the first group of light source pixels is lit up at the first moment, the second group of light source pixels is lit up at the second moment, and so on, to obtain multiple light beams with different optical path differences.

5. The Fourier transform spectrometer based on a coherent light source array as described in claim 1, characterized in that, The multiple light source pixels are circular in shape.

6. The Fourier transform spectrometer based on a coherent light source array as described in claim 1, characterized in that, The light source is a laser.

7. The Fourier transform spectrometer based on a coherent light source array as described in claim 1, characterized in that, The optical transmission device is an optical fiber.

8. A Fourier transform spectrometer based on a coherent light source array, characterized in that, It consists of a light source, a light transmission device, a control circuit, a coherent light source array, a detector, an amplification circuit, and a computer. The control circuit is electrically connected to the light transmission device and is used to control the on / off state of light in the light transmission device. The light transmission device has its starting end fixed to the light source and its ending end fixed to the coherent light source array. The light transmission device is used to transmit light emitted from the light source to the coherent light source array. The coherent light source array includes a substrate and multiple light source pixels, which are disposed on the substrate. The on / off state of the light source at each pixel in the coherent light source array at different times is controlled by a program, thereby obtaining light beams with different optical paths, where the optical path is the distance from the different light source pixels to the center of the sample. The detector is used to detect the photoelectric signal of the light beam generated by the coherent light source array after passing through the sample. The amplification circuit is connected to the detector and is used to record and amplify the photoelectric signal obtained by the detector. The computer is connected to the amplification circuit and has spectral analysis software installed on it for performing Fourier transforms.

Images