Multi-channel gallium arsenide optical fiber temperature measurement system based on area array detector

Abstract

The utility model relates to an optical fiber temperature measurement system, in particular to a multi-channel gallium arsenide optical fiber temperature measurement system based on an area array detector, which is used for solving the problems of short service life, high cost, insufficient temperature measurement range, low cost and the like of a light source module in the conventional multi-channel gallium arsenide optical fiber temperature measurement system. A spectrum light splitting module has the defect that a certain degree of spherical aberration affects the temperature measurement precision of a system. The multichannel gallium arsenide optical fiber temperature measurement system based on the area array detector comprises a light source module, a gallium arsenide temperature measurement module, a spectrum light splitting module and a data processing module.

Description

Technical Field

[0001] The utility model relates to an optical fiber temperature measurement system, in particular to a multi-channel gallium arsenide optical fiber temperature measurement system based on a planar array detector. Background Art

[0002] Fiber optic temperature measurement technology has excellent characteristics such as no electromagnetic interference, corrosion resistance, passive real-time monitoring, small installation size, and high sensitivity. It is very suitable for use in harsh environments such as flammable, explosive, space-constrained, and strong electromagnetic interference. In recent years, it has been widely used in power, medical, aerospace and other fields. This technology uses the physical effect of fiber optic temperature sensor materials on light, and analyzes the light intensity data to obtain the temperature information of the sensor probe. There are many types of temperature sensor probes. At present, the more mainstream ones are fluorescent material probes and semiconductor gallium arsenide probes. However, due to the inherent limitations of fluorescent materials and intensity demodulation principles, it is difficult for fluorescent fiber optic temperature measurement systems to make breakthroughs in temperature measurement range, channel consistency, and interchangeability.

[0003] The fiber optic temperature measurement system using semiconductor gallium arsenide probes obtains temperature information by demodulating the absorption spectrum. When the light source emits multiple wavelengths of light to irradiate the gallium arsenide chip, the chip will absorb the incident light of different wavelengths according to the temperature, and reflect the light of the wavelength that is not absorbed. Therefore, by detecting the spectrum of the reflected light, the measured temperature can be inferred. In the gallium arsenide fiber optic temperature measurement system, gallium arsenide is used as a sensing material with stable performance, high reliability, good consistency and interchangeability, and the sensor is small in size and can work for a long time. It is a passive probe and a very safe component in the electrical system. In addition, for the spectral analysis method, changes in intensity-related parameters such as light source, transmission efficiency, coupling degree, and fiber bending will not affect the results of temperature measurement. Semiconductor gallium arsenide fiber optic temperature measurement technology can well make up for the shortcomings of fluorescent fiber optic temperature measurement technology, and has been widely used in temperature monitoring of high-precision equipment and large ultra-high voltage oil-immersed transformer windings at home and abroad.

[0004] However, the existing multi-channel GaAs optical fiber temperature measurement system has the following problems:

[0005] (1) Each temperature measurement channel is equipped with an optical switch, and all light sources are always on. The light source is controlled by the program to open and close the optical switch, which shortens the service life of the light source. At the same time, the optical switch increases the cost;

[0006] (2) Since the absorption spectrum of gallium arsenide semiconductor at room temperature is in the near-infrared band, the light source is usually an LED or LD with a central wavelength in the near-infrared band. In addition to the high price, the emission spectrum range of these two light sources is relatively short, generally tens of nanometers or less than ten nanometers, resulting in an insufficient temperature measurement range;

[0007] (3) Spectral splitting modules mostly adopt a CT optical path structure, using a spherical mirror for collimation and focusing. However, the spherical mirror cannot cancel out the spherical aberration terms in the system. Although the CT optical path can correct the spherical aberration to a certain level, the spherical aberration still exists, affecting the temperature measurement accuracy of the system. Utility Model Content

[0008] The purpose of the utility model is to solve the shortcomings of the existing multi-channel gallium arsenide optical fiber temperature measurement system, such as the short service life of the light source module, the high cost, the insufficient temperature measurement range, and the spectral splitting module having a certain degree of spherical aberration affecting the temperature measurement accuracy of the system, and to provide a multi-channel gallium arsenide optical fiber temperature measurement system based on a planar array detector.

[0009] In order to solve the deficiencies of the above-mentioned prior art, the present invention provides the following technical solutions:

[0010] A multi-channel gallium arsenide optical fiber temperature detection device based on a planar array detector, which is special in that it includes a light source module, a gallium arsenide temperature measurement module, a spectrum splitting module and a data processing module;

[0011] The light source module includes N halogen lamps connected in parallel, N is an integer greater than 1, and the N halogen lamps work in a time sequence; the gallium arsenide temperature measurement module includes N temperature measurement units respectively connected to the N halogen lamps;

[0012] The spectral spectrometer module comprises an inlet optical fiber array, a collimator, a transmission grating, a focusing lens group and a planar array detector which are sequentially arranged along the propagation direction of the light beams output by the N temperature measuring units; the output ends of the N temperature measuring units are arranged in an array to form the inlet optical fiber array for outputting light beams, and the collimator, the transmission grating, the focusing lens group and the planar array detector are respectively used for collimating, diffracting, splitting, focusing and collecting the light beams; the collimator is an achromatic cemented lens composed of a concave lens and a convex lens, and the focusing lens group comprises a plano-convex lens, a double concave lens and a double convex lens which are sequentially arranged along the propagation direction of the light beams output by the temperature measuring units, and the convex surface of the plano-convex lens is the incident surface, and the flat surface is the exit surface;

[0013] The data processing module is connected to the area array detector and is used to convert the spectrum information into temperature values.

[0014] Furthermore, the transmission grating is a transmission plane diffraction grating, the angle between the transmission grating and the optical axis of the collimating lens is 45°, and the angle between the optical axis of the focusing lens group and the transmission grating is 24.6°.

[0015] Furthermore, each of the temperature measuring units includes a first optical fiber, a second optical fiber, a third optical fiber, a multimode optical fiber coupler and a gallium arsenide sensor probe; each of the halogen lamps is connected to the first port of the multimode optical fiber coupler through the first optical fiber for inputting a light beam, the second port of the multimode optical fiber coupler is connected to the gallium arsenide sensor probe through the second optical fiber, and the third port is connected to the import optical fiber array through the third optical fiber for transmitting the incident light beam to the gallium arsenide sensor probe, and coupling the optical signal returned by the gallium arsenide sensor probe into the third optical fiber and inputting it into the corresponding channel of the import optical fiber array.

[0016] Furthermore, the gallium arsenide sensing probe includes a semiconductor gallium arsenide wafer and an outer layer of reflective material, the semiconductor gallium arsenide wafer has a thickness of 100 to 200 μm, and the incident surface is coated with a high-transmittance dielectric film, and the reflection surface is coated with a high-reflectivity dielectric film. The semiconductor gallium arsenide wafer is bonded to one end of the second optical fiber by a glue that does not change color at high temperatures, and the outer layer of reflective material is solidified on the surface of the semiconductor gallium arsenide wafer and the connection between the semiconductor gallium arsenide wafer and the second optical fiber through a baking process.

[0017] Furthermore, the core diameters of the first optical fiber and the third optical fiber are equal and smaller than the core diameter of the second optical fiber.

[0018] Furthermore, the number of grating lines of the transmission grating is 1200 line pairs / mm, and the reference wavelength λ is 870nm.

[0019] Compared with the prior art, the beneficial effects of the utility model are:

[0020] (1) The utility model is a multi-channel gallium arsenide fiber optic temperature measurement system based on a planar array detector, which adopts a halogen lamp as a light source. The luminous spectrum range is relatively wide, generally several hundred nanometers. At the same time, it is combined with an efficient multi-mode fiber optic coupler, which can not only couple as much light energy as possible into the gallium arsenide temperature measurement module, but also achieve a larger temperature measurement range.

[0021] (2) The utility model discloses a multi-channel gallium arsenide fiber optic temperature measurement system based on a planar array detector. In the spectrum splitting module, an achromatic cemented lens is used as a collimating lens. The achromatic cemented lens is composed of a crown glass with a low dispersion rate and a flint glass with a high dispersion rate. The collimating lens can eliminate spherical aberration and coma at the same time. The Cooke three-piece structure is used as a focusing lens group. This makes the system imaging aberration small and the resolution high, which can significantly improve the imaging quality.

[0022] (3) The utility model is a multi-channel GaAs fiber optic temperature measurement system based on a planar array detector. When the planar array detector is used to receive spectral signals, the spectral images and data returned by the GaAs sensor probes of multiple channels can be displayed and collected simultaneously, thereby simplifying the data processing flow of the data processing module and improving efficiency. In addition, compared with the linear array detector with a narrow receiving surface, the planar array detector has many photosensitive pixels and a large photon receiving area, which greatly reduces the difficulty of system installation and adjustment. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 The utility model is a structural schematic diagram of an embodiment of a multi-channel gallium arsenide optical fiber temperature measurement system based on a planar array detector.

[0024] The reference numerals are explained as follows: 1-light source module, 11-halogen lamp; 2-gallium arsenide temperature measurement module, 21-first optical fiber, 22-second optical fiber, 23-third optical fiber, 24-multimode optical fiber coupler, 25-gallium arsenide sensor probe; 3-spectral spectrometer module, 31-introduction optical fiber array, 32-collimating mirror, 33-transmission grating, 34-focusing lens group, 341-plano-convex lens, 342-double concave lens, 343-double convex lens, 35-array detector. DETAILED DESCRIPTION

[0025] The utility model is further described below in conjunction with the accompanying drawings and specific embodiments.

[0026] like Figure 1 As shown, a multi-channel gallium arsenide optical fiber temperature measurement system based on a planar array detector includes a light source module 1, a gallium arsenide temperature measurement module 2, a spectrum splitting module 3 and a data processing module. Figure 1 The data processing module is not shown.

[0027] The light source module 1 includes N halogen lamps 11 connected in parallel. The N halogen lamps 11 work in sequence. In this embodiment, N is 16. In other embodiments, the number can be adjusted according to demand.

[0028] The gallium arsenide temperature measurement module 2 includes N temperature measurement units respectively connected to N halogen lamps 11; each temperature measurement unit includes a first optical fiber 21, a second optical fiber 22, a third optical fiber 23, a multimode optical fiber coupler 24 and a gallium arsenide sensor probe 25; the first optical fiber 21, the second optical fiber 22, and the third optical fiber 23 are all made of high-temperature resistant quartz multimode optical fibers coated with polyimide, the core diameters of the first optical fiber 21 and the third optical fiber 23 are 100 μm, and the core diameter of the second optical fiber 22 is 200 μm; the gallium arsenide sensor probe 25 includes a semiconductor gallium arsenide wafer and an outer layer of reflective material, the thickness of the semiconductor gallium arsenide wafer is 100-200 μm, and the incident surface is coated with a high-transmittance dielectric film, and the reflection surface is coated with a high-reflectivity dielectric film, the semiconductor gallium arsenide wafer is bonded to one end of the second optical fiber 22 by a glue that does not change color at high temperature, and the outer layer of reflective material is solidified on the surface of the semiconductor gallium arsenide wafer and the connection between the semiconductor gallium arsenide wafer and the second optical fiber 22 through a baking process.

[0029] Figure 1 Only the multimode fiber coupler 24 of the first temperature measuring unit is shown. Taking the first temperature measuring unit as an example, each halogen lamp 11 is connected to the first port of the multimode fiber coupler 24 through the first optical fiber 21 for inputting a light beam, the second port of the multimode fiber coupler 24 is connected to the gallium arsenide sensor probe 25 through the second optical fiber 22, and the third port is connected to the import optical fiber array 31 through the third optical fiber 23 for transmitting the incident light beam to the gallium arsenide sensor probe 25, and coupling the optical signal returned by the gallium arsenide sensor probe 25 into the third optical fiber 23 and inputting it into the corresponding channel of the import optical fiber array 31.

[0030] The spectral splitting module 3 includes an inlet optical fiber array 31, a collimator 32, a transmission grating 33, a focusing lens group 34 and a planar array detector 35 which are sequentially arranged along the propagation direction of the light beams output by the N temperature measuring units; in this embodiment, the collimator 32 is an achromatic cemented lens composed of a concave lens and a convex lens, the material of the concave lens is crown glass H-ZF2, and the material of the convex lens is flint glass H-K9L; the transmission grating 33 is a transmission plane diffraction grating, and the number of grating lines is 1 200 line pairs / mm, the reference wavelength λ is 870nm, the angle between the optical axis of the transmission grating 33 and the collimator 32 is 45°; the focusing lens group 34 is a Cooke three-piece structure, which includes a plano-convex lens 341, a biconcave lens 342 and a biconvex lens 343 arranged in sequence along the propagation direction of the light beam output by the temperature measuring unit, the convex surface of the plano-convex lens 341 is the incident surface, and the flat surface is the exit surface, and the angle between the optical axis of the focusing lens group 34 and the transmission grating 33 is 24.6°.

[0031] The output ends of the N temperature measuring units are arranged in an array manner to form an import fiber array 31 for outputting a light beam. Specifically, the import fiber array 31 is formed by 16 62.5 / 125 μm optical fibers arranged in an array manner; the collimator 32, transmission grating 33, focusing lens group 34, and planar array detector 35 are respectively used for collimating, diffracting, splitting, focusing, and collecting the light beam.

[0032] The data processing module is connected to the array detector 35 and is used to perform real-time data processing on the spectral information collected by the array detector 35 and obtain temperature measurement results.

Claims

1. A multi-channel gallium arsenide optical fiber temperature measurement system based on an array detector, characterized in that: It comprises a light source module (1), a gallium arsenide temperature measurement module (2), a spectrum splitting module (3) and a data processing module; The light source module (1) comprises N halogen lamps (11) connected in parallel, N being an integer greater than 1, and the N halogen lamps (11) operate in a time sequence; the gallium arsenide temperature measurement module (2) comprises N temperature measurement units respectively connected to the N halogen lamps (11); The spectral splitting module (3) comprises an inlet optical fiber array (31), a collimator (32), a transmission grating (33), a focusing lens group (34) and a planar array detector (35) which are sequentially arranged along the propagation direction of the light beams output by the N temperature measuring units; the output ends of the N temperature measuring units are arranged in an array manner to form the inlet optical fiber array (31) for outputting light beams; the collimator (32), the transmission grating (33), the focusing lens group (34) and the planar array detector (35) are respectively used for collimating, diffracting, splitting, focusing and collecting the light beams; the collimator (32) is an achromatic cemented lens composed of a concave lens and a convex lens; the focusing lens group (34) comprises a plano-convex lens (341), a bi-concave lens (342) and a bi-convex lens (343) which are sequentially arranged along the propagation direction of the light beams output by the temperature measuring units; the convex surface of the plano-convex lens (341) is the incident surface, and the flat surface is the exit surface; The data processing module is connected to the area array detector (35) and is used to convert the spectrum information into a temperature value.

2. According to claim 1, a multi-channel gallium arsenide optical fiber temperature measurement system based on a planar array detector is characterized in that: The transmission grating (33) is a transmission-type plane diffraction grating, the angle between the transmission grating (33) and the optical axis of the collimating mirror (32) is 45°, and the angle between the optical axis of the focusing lens group (34) and the transmission grating (33) is 24.6°.

3. The multi-channel gallium arsenide optical fiber temperature measurement system based on area array detector according to claim 2 is characterized in that: Each of the temperature measurement units comprises a first optical fiber (21), a second optical fiber (22), a third optical fiber (23), a multimode optical fiber coupler (24) and a gallium arsenide sensor probe (25); each of the halogen lamps (11) is connected to a first port of the multimode optical fiber coupler (24) via the first optical fiber (21) for inputting a light beam, a second port of the multimode optical fiber coupler (24) is connected to the gallium arsenide sensor probe (25) via the second optical fiber (22), and a third port is connected to an inlet optical fiber array (31) via a third optical fiber (23) for transmitting an incident light beam to the gallium arsenide sensor probe (25), and coupling an optical signal returned by the gallium arsenide sensor probe (25) into the third optical fiber (23) and inputting the optical signal into a corresponding channel of the inlet optical fiber array (31).

4. The multi-channel gallium arsenide optical fiber temperature measurement system based on area array detector according to claim 3 is characterized in that: The gallium arsenide sensing probe comprises a semiconductor gallium arsenide wafer and an outer layer of reflective material. The semiconductor gallium arsenide wafer has a thickness of 100 to 200 μm, and the incident surface is plated with a high-transmittance dielectric film, and the reflective surface is plated with a high-reflectivity dielectric film. The semiconductor gallium arsenide wafer is bonded to one end of the second optical fiber (22) by an adhesive that does not change color at high temperatures, and the outer layer of reflective material is solidified on the surface of the semiconductor gallium arsenide wafer and at the connection between the semiconductor gallium arsenide wafer and the second optical fiber (22) through a baking process.

5. The multi-channel gallium arsenide optical fiber temperature measurement system based on area array detector according to claim 4, characterized in that: The core diameters of the first optical fiber (21) and the third optical fiber (23) are equal and smaller than the core diameter of the second optical fiber (22).

6. A multi-channel gallium arsenide optical fiber temperature measurement system based on a planar array detector according to any one of claims 1 to 5, characterized in that: The number of grating lines of the transmission grating (33) is 1200 line pairs / mm, and the reference wavelength λ is 870nm.

Images