A dual-channel adaptive background subtraction Golay detector

Abstract

This invention provides a dual-channel adaptive background subtraction Golay detector, belonging to the field of optical metrology and testing technology. The dual-channel adaptive background subtraction Golay detector includes a measurement channel, a reference channel, a gas balance chamber, and a processing circuit. The first gas response chamber in the measurement channel has a first absorption film layer in the middle and a first deformation film on its bottom surface. A light shield is provided above the reference channel. The second gas response chamber in the reference channel has a second absorption film layer in the middle and a second deformation film on its bottom surface. The gas balance chamber is connected to the first gas response chamber through a first venting channel and to the second gas response chamber through a second venting channel. The processing circuit is used to measure the capacitance of the measurement channel and the reference channel. This invention enables real-time environmental background radiation subtraction, improves the performance of the Golay detector, and allows the Golay detector to be applied in situations where environmental background radiation changes rapidly, thus expanding the application range of the Golay detector.

Description

Technical Field

[0001] This invention belongs to the field of optical metrology and testing technology, specifically relating to a dual-channel adaptive background subtraction Golay detector. Background Technology

[0002] The Golay detector is a classic uncooled, non-selective photoacoustic infrared terahertz detector. It primarily utilizes the characteristic that a gas increases in volume after absorbing infrared terahertz radiation to indicate the intensity of the radiation. The Golay detector can operate at room temperature and has advantages such as low modulation frequency, high sensitivity, and a wide spectral range. It is widely used in the detection of infrared terahertz radiation and can also serve as the core detector for infrared terahertz spectrometers.

[0003] A typical Golay detector consists of a probe and a signal acquisition and processing module. The probe includes a radiation focusing system, a radiation-response gas chamber, and a gas chamber deformation measurement system. Incident infrared terahertz radiation is focused by the radiation focusing system and then enters the radiation-response gas chamber. The radiation-response gas chamber converts the infrared terahertz radiation into a change in gas volume, which manifests as deformation of the deformation film within the chamber. The gas chamber deformation measurement system is primarily used to measure the deformation of the deformation film, converting the deformation into an electrical signal output. Currently, gas chamber deformation measurement systems mainly employ four measurement methods: optical schlieren measurement, optical interferometry measurement, capacitance measurement, and tunneling effect measurement. The signal acquisition and processing module primarily amplifies and filters the probe's output signal.

[0004] Currently, the main research and products of the Gao Lai detector are as follows: Chinese patent CN101038213A discloses a dual-cavity balanced pneumatic room temperature infrared detector, including an absorption cavity, an infrared window covering the absorption cavity, a sensitive film on the absorption cavity shell, and an element for detecting the deformation of the sensitive film. A balance cavity is set on the other side of the sensitive film, and the gas pressure in the absorption cavity and the balance cavity is the same. The element for detecting the deformation of the sensitive film is set in the absorption cavity or the balance cavity. US patent US7485870B2 discloses a pneumatic infrared detector, which includes a sensitive cavity and a parameter. A tunneling aerodynamic infrared sensor detects infrared radiation by measuring the aerodynamic expansion of its sensitive cavity. The principle is that after the sensitive cavity absorbs infrared radiation energy, its temperature rises, causing aerodynamic expansion. A reference cavity is mechanically connected to the sensitive cavity and is used to control the aerodynamic expansion of the sensitive cavity. Stanford University and the U.S. Space Microelectronics Technology Center designed and developed an uncooled tunneling aerodynamic infrared sensor, which mainly consists of an infrared absorption layer with very low heat capacity, a sensitive thin film, a tunnel tip, and a closed-loop feedback circuit. Its basic idea is to use the electrostatic force feedback from the tunnel position to prevent the sensitive thin film from moving, and to detect infrared rays by measuring this electrostatic force. Another function of the feedback circuit is to control the static voltage of the two plates when the ambient temperature and pressure change, thereby controlling the sensitive film to be in the required position. The feedback circuit of this detector is a complex servo system, and its reliability and speed directly affect the normal operation of the device. Moreover, the feedback circuit only ensures that the device is in normal working condition when the ambient temperature and pressure change, but it cannot eliminate the influence of these changes. A paper titled "Computer Simulation of Micromechanical Pneumatic Infrared Detector" from Beijing University of Technology introduces a miniature pneumatic infrared detector that can operate at room temperature. It is based on the absorption of infrared radiation in a specific band by a gas medium and then using non-radiative pneumatic motion. The physical basis for the excitation and generation of a series of thermal effects can obtain signals containing infrared radiation source information. A finite element model that conforms to the device's working mode was established. The mechanical behavior of the device and the temperature field distribution of the gas medium were analyzed using the fluid-thermal-structure coupling method. The influence of different structural parameters on the device performance was also discussed. This provides a theoretical basis for developing uncooled pneumatic infrared detectors with wavelength selectivity. Currently, the typical product of the Golay detector is the GC-1T Golay detector produced by the Russian company TYDEX. Its gas chamber deformation measurement system uses the optical schlieren method to measure the deformation of the gas chamber deformation film.

[0005] The detectors designed in the above studies are all single-channel. For ambient background radiation, the only way to reduce the impact of ambient background radiation on the effective signal is to measure the ambient background radiation first and then perform background subtraction. However, this method has great limitations in situations where the ambient background radiation changes rapidly and will introduce large measurement errors. Currently, no Galey detector or pneumatic detector can achieve real-time ambient background elimination. Summary of the Invention

[0006] The purpose of this invention is to solve the problem that existing Golay detectors cannot achieve real-time background subtraction, and to provide a dual-channel adaptive background subtraction Golay detector.

[0007] To achieve the above objectives, the technical solution provided by this invention is:

[0008] A dual-channel adaptive background subtraction Golay detector is provided, including a measurement channel, a reference channel, a gas balance chamber, and a processing circuit. The measurement channel includes a first optical cone, a first gas response chamber, and a first deformation capacitance measurement system arranged sequentially from top to bottom. The central axes of the first optical cone and the first gas response chamber are both located on a first central optical axis. A first absorption film layer for absorbing radiation and heating the gas inside the first gas response chamber is provided in the middle of the first gas response chamber. A first deformation film is provided on the bottom surface of the first gas response chamber. The first deformation capacitance measurement system includes a first upper electrode and a first lower electrode separated by a support ring, and the first deformation film is the first upper electrode. A light shield is provided above the reference channel to block infrared terahertz radiation. The detector also includes a second optical cone, a second gas response chamber, and a second deformation capacitance measurement system arranged sequentially from top to bottom. The central axes of the second optical cone and the second gas response chamber are both located on a second central optical axis. The second gas response chamber has a second absorption film layer in the middle for absorbing radiation and heating the gas inside the second gas response chamber. The bottom surface of the second gas response chamber has a second deformation film. The second deformation capacitance measurement system includes a second upper electrode and a second lower electrode separated by a support ring. The second deformation film is the second upper electrode. The first light cone and the first gas response chamber, and the second light cone and the second gas response chamber are separated by window glass. The gas balance chamber is located between the first gas response chamber and the second gas response chamber. It is connected to the first gas response chamber through a first venting channel and to the second gas response chamber through a second venting channel. The first gas response chamber, the first venting channel, the second gas response chamber, the second venting channel, and the gas balance chamber form a gas-sealed space and are filled with gas. The processing circuit is electrically connected to the first deformation capacitance measurement system and the second deformation capacitance measurement system respectively, and is used to measure the capacitance of the measurement channel and the reference channel.

[0009] Furthermore, the first and second light cones are processed from the same aluminum plate, and both have a downward tapering cone shape.

[0010] Furthermore, the tapered sidewalls that taper downwards are blackened.

[0011] Furthermore, support rings are provided between the first upper electrode and the first lower electrode, and between the second upper electrode and the second lower electrode. Silicon substrates are provided between the bottom surface of the window glass and the upper surfaces of the two support rings. The first gas response chamber and the second gas response chamber are both "convex" structures processed from the two silicon substrates. The "convex" structure is composed of two hollow cylinders with different radii. The radius of the upper hollow cylinder is larger than that of the lower hollow cylinder, and the radius of the upper hollow cylinder is consistent with the radius of the downwardly tapered lower bottom surface.

[0012] Furthermore, channels are provided on the sidewalls of the two silicon substrates that are close to each other, and the two channels, together with the bottom surface of the window glass, form the first drainage channel and the second drainage channel, respectively.

[0013] Furthermore, both the first absorption film layer and the second absorption film layer are disposed on the bottom surface of the inner cavity of the first hollow cylinder located above.

[0014] Furthermore, the volume of the gas balance chamber is greater than the volume of the first gas response chamber and the volume of the second gas response chamber, respectively.

[0015] Furthermore, a base plate is provided below the support ring; the gas-sealed space is composed of the base plate, two silicon substrates and window glass, and is filled with He or Xe gas.

[0016] Furthermore, the lower surfaces of both the first and second deformation films are coated with metal film layers; the upper surface portion of the base plate located below the first upper electrode is coated with a metal film layer, serving as the first lower electrode; the upper surface portion of the base plate located below the second upper electrode is coated with a metal film layer, serving as the second lower electrode.

[0017] The advantages of this invention are:

[0018] 1. This invention presents a dual-channel adaptive background subtraction Golay detector. By designing two channels—a measurement channel and a reference channel—along with a gas balance chamber, it achieves real-time background radiation subtraction, solving the problem of large measurement errors in traditional single-channel detectors when the environmental background changes rapidly. The measurement channel detects both infrared terahertz radiation and ambient background radiation, while the reference channel, through a light-shielding shield, detects only ambient background radiation. Combined with real-time background subtraction via processing circuitry, this significantly improves measurement accuracy. The gas balance chamber is connected to the first and second gas response chambers, ensuring consistent gas environments in both channels and enhancing the detector's adaptability, making it suitable for environments with rapidly changing backgrounds. The detector designed in this invention exhibits high precision, high reliability, and wide applicability in the field of infrared terahertz radiation detection, and expands the application scenarios of Golay detectors.

[0019] 2. In this invention, since the first deformation film and the second deformation film are used as the first upper electrode and the second upper electrode, respectively, the first deformation capacitance measurement system and the second deformation capacitance measurement system have high sensitivity, can accurately detect minute deformation signals, and significantly improve the measurement accuracy. Attached Figure Description

[0020] The features and advantages of the invention will become more readily apparent from the following description with reference to the accompanying drawings, which are not drawn to scale and some features are enlarged or reduced to show details of specific parts.

[0021] Figure 1 This is a schematic diagram of the structure of the dual-channel adaptive background subtraction Golay detector of the present invention;

[0022] Figure 2 This is a top view of the first light cone in this invention;

[0023] Figure 3 This is a front view of the first gas response chamber and the second gas response chamber in this invention;

[0024] Figure 4 This is a top view of the first gas response chamber and the second gas response chamber in this invention;

[0025] Figure 5 This is a front view of the first support ring in this invention;

[0026] Figure 6 This is a top view of the first support ring in this invention;

[0027] In the diagram: 100 - Window glass; 200 - Aluminum plate; 300 - Silicon substrate; 400 - Base plate; 500 - Light shield; 600 - Measurement channel; 610 - First light cone; 620 - First absorption film layer; 630 - First deformation film; 640 - First venting channel; 650 - First gas response chamber; 651 - First hollow cylinder; 652 - Second hollow cylinder; 660 - First upper electrode; 670 - First lower electrode; 680 - First support ring; 681 - Outer ring of the first support ring; 682 - Inner ring of the first support ring; 700 - Reference channel; 710 - Second light cone; 720 - Second absorption film layer; 730 - Second deformation film; 740 - Second venting channel; 750 - Second gas response chamber; 760 - Second upper electrode; 770 - Second lower electrode; 780 - Second support ring; 800 - Gas balance chamber; 900 - Processing circuit. Detailed Implementation

[0028] The present invention will now be described in detail with reference to the accompanying drawings and exemplary embodiments thereof. It should be noted that the following detailed description of the present invention is for illustrative purposes only and is not intended to limit the scope of the invention.

[0029] To address the problem that existing Golay detectors cannot achieve real-time background subtraction, this embodiment provides a dual-channel adaptive background subtraction Golay detector.

[0030] like Figure 1 As shown, a dual-channel adaptive background subtraction Golay detector includes a measurement channel 600, a reference channel 700, a gas balance chamber 800, and a processing circuit 900.

[0031] like Figure 1 As shown, the measurement channel 600 includes a first optical cone 610, a first gas response chamber 650, and a first deformation capacitance measurement system arranged sequentially from top to bottom. The central axes of the first optical cone 610 and the first gas response chamber 650 are both located on the first central optical axis. The first gas response chamber 650 has a first absorption film layer 620 in the middle for absorbing radiation and heating the gas inside the first gas response chamber 650. The bottom surface of the first gas response chamber 650 has a first deformation film 630. The first deformation capacitance measurement system includes a first upper electrode 660 and a first lower electrode 670 separated by a support ring. The first upper electrode 660 and the first lower electrode 670 are connected by bonding technology for subsequent measurement. The first deformation film 630 is the first upper electrode 660.

[0032] like Figure 1 As shown, a light shield 500 is provided above the reference channel 700 to block infrared terahertz radiation; the reference channel 700 includes a second light cone 710, a second gas response chamber 750, and a second deformation capacitance measurement system arranged sequentially from top to bottom. The central axes of the second light cone 710 and the second gas response chamber 750 are both located on the second central optical axis; a second absorption film 720 is provided in the middle of the second gas response chamber 750 for absorbing radiation and heating the gas inside the second gas response chamber 750; a second deformation film 730 is provided on the bottom surface of the second gas response chamber 750; the second deformation capacitance measurement system includes a second upper electrode 760 and a second lower electrode 770 separated by a support ring; the second upper electrode 760 and the second lower electrode 770 are connected by bonding technology for subsequent measurement; the second deformation film 730 is the second upper electrode 760.

[0033] like Figure 1 , 3As shown in Figure 4, the first light cone 610 and the first gas response chamber 650, and the second light cone 710 and the second gas response chamber 750 are all separated by window glass 100; the gas balance chamber 800 is located between the first gas response chamber 650 and the second gas response chamber 750, and is connected to the first gas response chamber 650 through the first venting channel 640, and is connected to the second gas response chamber 750 through the second venting channel 740; the first gas response chamber 650, the first venting channel 640, the second gas response chamber 750, the second venting channel 740 and the gas balance chamber 800 form a gas-sealed space and are filled with gas.

[0034] like Figure 1 As shown, the processing circuit 900 is electrically connected to the first deformation capacitance measurement system and the second deformation capacitance measurement system, respectively, and is used to measure the capacitance of the measurement channel 600 and the reference channel 700. The processing circuit 900 can use a conventional circuit capable of measuring capacitance. In the deformation capacitance measurement system, the first deformation film 630 serves as the first upper electrode 660, forming a capacitance with the first lower electrode 670; the second deformation film 730 serves as the second upper electrode 760, forming a capacitance with the second lower electrode 770. The first deformation film 630 and the second deformation film 730 have high sensitivity and can accurately detect minute deformation signals. When the gas in the first gas response chamber 650 deforms due to infrared terahertz radiation, the minute displacement of the first deformation film 630 and the second deformation film 730 will cause a change in capacitance, which can be accurately measured by the processing circuit 900.

[0035] The dual-channel adaptive background subtraction Golay detector proposed in this embodiment achieves real-time background radiation subtraction by designing two channels, a measurement channel 600 and a reference channel 700, and an innovative structure of a gas balance chamber 800. This solves the problem that traditional single-channel detectors cannot achieve real-time background elimination. The measurement channel 600 is used to detect infrared terahertz radiation and ambient background radiation, while the reference channel 700 is shielded by a light shield 500 and only detects ambient background radiation. Combined with the processing circuit 900, background subtraction is performed in real time, significantly improving measurement accuracy. The gas balance chamber 800 is connected to the first gas response chamber 650 and the second gas response chamber 750 through the first venting channel 640 and the second venting channel 740, ensuring consistent gas environments in both channels and enhancing the detector's adaptive capability, making it suitable for situations with rapidly changing ambient backgrounds. The first and second deformation capacitance measurement systems have high sensitivity and can accurately detect minute deformation signals. The overall structure is compact, and the gas-sealed design ensures long-term stability. The detector designed in this embodiment has high precision, high reliability and wide applicability in the field of infrared terahertz radiation detection, and expands the application scenarios of the Golay detector.

[0036] The measurement principle of this invention is as follows:

[0037] In the measurement channel 600, the incident radiation (including infrared terahertz radiation and ambient background radiation) is initially shaped by the first light cone 610 and then converged through the window glass 100 to the first absorption film 620 in the first gas response chamber 650. The first absorption film 620 absorbs the radiation and heats the gas in the first gas response chamber 650. The gas is heated and expands in volume, causing the first deformation film 630 to deform, which in turn causes the capacitance measurement value of the first deformation capacitance measurement system to change.

[0038] In the reference channel 700, the incident radiation (ambient background radiation) is initially shaped by the second light cone 710 and then converged through the window glass 100 to the second absorption film layer 720 of the first gas response chamber 650. The second absorption film layer 720 absorbs the radiation and heats the gas in the second gas response chamber 750. The gas is heated and expands in volume, causing the second deformation film 730 to deform, which in turn causes the capacitance measurement value of the second deformation capacitance measurement system to change.

[0039] like Figure 1 , 2 As shown, the first light cone 610 and the second light cone 710 are processed on the same aluminum plate 200, and both have a downward tapering cone structure, with the downward tapering cone sidewalls treated with blackening. Blackening treatment can significantly reduce light reflection on the metal surface.

[0040] like Figure 1 , 3 As shown, support rings are provided on both sides of the window glass 100, and between the first upper electrode 660 and the first lower electrode, the second upper electrode 760 and the second lower electrode 770, respectively. Silicon substrates 300 are provided between the window glass 100 and the upper surfaces of the two support rings. The first gas response chamber 650 and the second gas response chamber 750 are both "convex" structures formed by photolithography or etching processes from the two silicon substrates 300. The "convex" structure is composed of two hollow cylinders with different radii. The radius of the upper first hollow cylinder 651 is larger than the radius of the lower second hollow cylinder 652, and the radius of the upper first hollow cylinder 651 is consistent with the radius of the downward tapered lower bottom surface.

[0041] like Figure 1 , 3As shown in Figure 4, channels are provided on the sidewalls of the two silicon substrates 300 that are close to each other. The two channels, together with the bottom surface of the window glass 100, form the first leakage channel 640 and the second leakage channel 740, respectively. Through the first leakage channel 640 and the second leakage channel 740, gas exchange can be carried out between the first gas response chamber 650 of the measurement channel 600 and the second gas response chamber 750 of the reference channel 700 through the gas balance chamber 800. This maintains a consistent gas environment between the two channels, allowing the detector to adaptively adjust the background subtraction. Even if the ambient background radiation changes, the detector can adjust in real time to ensure the accuracy of the measurement results.

[0042] like Figure 1 As shown, the first absorption film layer 620 and the second absorption film layer 720 are both disposed on the bottom surface of the inner cavity of the upper first hollow cylinder 651. The first absorption film layer 620 and the second absorption film layer 720 are made of absorbing materials such as carbon nanotubes and nickel black.

[0043] In this embodiment, the window glass 100 is made of quartz glass or high-resistivity silicon window film.

[0044] like Figure 1 As shown, the volume of the gas balance chamber 800 is larger than that of the first gas response chamber 650 and the second gas response chamber 750, respectively. This can buffer pressure fluctuations, stabilize the gas environment, and quickly balance the pressure, which significantly improves the measurement accuracy, response speed and long-term stability of the detector. This allows the Golay detector to maintain high-precision measurement even in situations where the ambient background radiation changes rapidly.

[0045] like Figure 1 As shown, the support rings in the measurement channel 600 and the reference channel 700 may each include a first support ring 680 and a second support ring 780. The first upper electrode 660 and the first lower electrode 670, and the second upper electrode 760 and the second lower electrode 770 are separated by the first support ring 680 and the second support ring 780. A base plate 400 is provided below the first support ring 680 and the second support ring 780. The gas-sealed space is composed of the base plate 400, two silicon substrates 300 and window glass 100, and is filled with He gas or Xe gas. This can ensure the stability of the gas environment inside the detector, effectively prevent the influence of gas leakage or changes in the external gas environment on the measurement results, and improve the long-term stability and reliability of the detector.

[0046] The first and second venting channels 640 and 740 are primarily used to counteract low-frequency environmental noise interference. The time constants of the venting channels can be controlled by adjusting their diameters and lengths; typically, the time constant is approximately 100,000 times the gas response time constant. The time constant of the venting channels can be estimated using the following formula:

[0047] τ leak =128μ air Vd / πD z 4 p

[0048] Where: τ leak Represents the time constant of the discharge channel, in milliseconds (ms); μ air The viscosity of air at room temperature is 1.8 × 10⁻⁵ Pa·s; V represents the volume of the gas response chamber, in m³. 3 ;d represents the length of the discharge channel, in meters; D z The diameter of the discharge channel is represented in meters (m); p represents the static pressure, which is 10. 5 pa.

[0049] In this embodiment, the first deformation film 630 and the second deformation film 730 are made of concentrated borosilicate film or PET-ITO conductive film. The upper surface portion of the base plate 400 located below the first upper electrode 660 is coated with a metal film layer, serving as the first lower electrode 670; the upper surface portion of the base plate 400 located below the second upper electrode 760 is coated with a metal film layer, serving as the second lower electrode 770.

[0050] In other embodiments, the lower surface of the first deformation film 630 is coated with a metal film layer, which can serve as the first upper electrode 660, and the lower surface of the second deformation film 730 is coated with a metal film layer, which can serve as the second upper electrode 760.

[0051] Below is a specific example illustrating the structure of a dual-channel adaptive background subtraction Golay detector.

[0052] like Figure 2 As shown, aluminum plate 200 is an aluminum disc with a thickness of 6mm and a diameter of 14mm. The centers of the two downward-tapering cones are equidistant from the center of aluminum plate 200, with a center-to-center distance of 9mm. The upper radius of the two downward-tapering cones is 4mm, and the lower diameter is 2mm.

[0053] like Figure 3 , 4As shown, the silicon substrate 300 has a disk structure with a thickness of 1 mm and a diameter of 24 mm. A 12 mm diameter through-hole is photolithographically or etched concentrically on the silicon substrate 300, serving as one of the filling spaces of the gas balance chamber 800. The centers of the two convex structures are equidistant from the center of the silicon substrate 300, at a distance of 9 mm, and the centers of the two convex structures lie on the same diameter of the silicon substrate 300. The convex structure consists of two hollow cylinders with different base radii arranged concentrically. The upper hollow cylinder 651 has a base diameter of 2 mm and a height of 0.5 mm, while the lower hollow cylinder 652 has a base diameter of 1 mm and a height of 0.5 mm. A first drain channel 640 and a second drain channel 740 are processed on the upper surface of the silicon substrate 300 using photolithography. The first drain channel 640 and the second drain channel 740 connect a through hole with a diameter of 12 mm and two "convex" structures. The length of the first drain channel 640 and the second drain channel 740 is 2 mm, and the width and height are both 0.05 mm. Since the cross-sectional dimensions of the first drain channel 640 and the second drain channel 740 are very small, it is approximated here that the diameter of the first drain channel 640 and the second drain channel 740 is also 0.05 mm.

[0054] like Figure 5 , 6 As shown, the thickness of the first support ring 680 is 0.05 mm, the diameter of the outer ring 681 of the first support ring is 21 mm, and the diameter of the inner ring 682 of the first support ring is 23 mm. The materials can be quartz, silicon, etc.

[0055] The thickness of the second support ring 780 is 0.05mm, the outer diameter of the second support ring is 15mm, and the inner diameter of the second support ring is 13mm. Its material can be quartz, silicon, etc.

[0056] Before measurement, the capacitance conversion coefficients of measurement channel 600 and reference channel 700 are first obtained. Specifically, the infrared terahertz source is turned off, and the chopper is used to chop the ambient background radiation at a certain frequency. The processing circuit 900 is used to measure the capacitance response values ​​of measurement channel 600 and reference channel 700 respectively. The capacitance conversion coefficient k of measurement channel 600 and reference channel 700 is calculated according to the following formula:

[0057] k=C0C0′

[0058] Where: C0 represents the capacitance response value of measurement channel 600, in pF; C0′ represents the capacitance response value of reference channel 700, in pF.

[0059] In infrared terahertz radiation measurement, reference channel 700 is used to measure ambient background radiation, and measurement channel 600 is used to measure both infrared terahertz radiation and ambient background radiation. After subtracting the ambient background radiation using processing circuit 900 according to the following formula, the net capacitance response C of infrared terahertz radiation can be obtained:

[0060] C=C1-kC1′

[0061] Where: C represents the net capacitance response of infrared terahertz radiation, in pF; k represents the capacitance conversion coefficient of measurement channel 600 and reference channel 700; C1 represents the capacitance response value of measurement channel 600 under radiation irradiation, in pF; C1′ represents the capacitance response value of reference channel 700 under radiation irradiation, in pF.

[0062] The dual-channel adaptive background subtraction Golay detector provided in this embodiment can realize real-time environmental background radiation subtraction, improve the performance of the Golay detector, and enable the Golay detector to be applied in situations where environmental background radiation changes rapidly, thus expanding the application scope of the Golay detector.

[0063] Finally, it should be noted that the features mentioned and / or shown in the above description of exemplary embodiments of the present invention can be combined in the same or similar manner with one or more other embodiments, combined with features in other embodiments, or substituted for corresponding features in other embodiments. These combined or substituted technical solutions should also be considered to be included within the scope of protection of the present invention.

Claims

1. A dual-channel adaptive background subtraction Golay detector, characterized in that, include: The measurement channel (600) includes a first light cone (610), a first gas response chamber (650), and a first deformation capacitance measurement system arranged sequentially from top to bottom. The central axes of the first light cone (610) and the first gas response chamber (650) are both located on the first central optical axis. The first gas response chamber (650) has a first absorption film layer (620) in the middle for absorbing radiation and heating the gas in the first gas response chamber (650). The bottom surface of the first gas response chamber (650) has a first deformation film (630). The first deformation capacitance measurement system includes a first upper electrode (660) and a first lower electrode (670) separated by a support ring. The first deformation film (630) is the first upper electrode (660). The reference channel (700) is equipped with a light shield (500) above it to block infrared terahertz radiation; The device includes a second light cone (710), a second gas response chamber (750), and a second deformation capacitance measurement system arranged sequentially from top to bottom. The central axes of the second light cone (710) and the second gas response chamber (750) are both located on the second central optical axis. The second gas response chamber (750) has a second absorption film layer (720) in the middle for absorbing radiation and heating the gas inside the second gas response chamber (750). The bottom surface of the second gas response chamber (750) has a second deformation film (730). The second deformation capacitance measurement system includes a second upper electrode (760) and a second lower electrode (770) separated by a support ring. The second deformation film (730) is the second upper electrode (760). The first light cone (610) and the first gas response chamber (650), and the second light cone (710) and the second gas response chamber (750) are all separated by window glass (100); A gas balance chamber (800) is located between the first gas response chamber (650) and the second gas response chamber (750), and is connected to the first gas response chamber (650) through a first venting channel (640) and to the second gas response chamber (750) through a second venting channel (740); the first gas response chamber (650), the first venting channel (640), the second gas response chamber (750), the second venting channel (740) and the gas balance chamber (800) form a gas-sealed space and are filled with gas; The processing circuit (900) is electrically connected to the first deformation capacitance measurement system and the second deformation capacitance measurement system, respectively, and is used to measure the capacitance of the measurement channel (600) and the reference channel (700).

2. The dual-channel adaptive background subtraction Golay detector according to claim 1, characterized in that, The first light cone (610) and the second light cone (710) are processed on the same aluminum plate (200), and both have a downward tapering cone structure.

3. A dual-channel adaptive background subtraction Golay detector according to claim 2, characterized in that, The tapered sidewalls that taper downwards are blackened.

4. A dual-channel adaptive background subtraction Golay detector according to claim 2, characterized in that, Support rings are provided between the first upper electrode and the first lower electrode, and between the second upper electrode and the second lower electrode. Silicon substrates (300) are provided between the bottom surface of the window glass (100) and the upper surfaces of the two support rings. The first gas response chamber (650) and the second gas response chamber (750) are both "convex" structures processed from the two silicon substrates (300). The "convex" structure is composed of two hollow cylinders with different radii. The radius of the first hollow cylinder (651) located above is greater than the radius of the second hollow cylinder (652) located below, and the radius of the first hollow cylinder (651) located above is consistent with the radius of the downwardly tapered lower bottom surface.

5. A dual-channel adaptive background subtraction Golay detector according to claim 4, characterized in that, Each of the two silicon substrates (300) has a channel on one side wall that is close to each other. The two channels and the bottom surface of the window glass (100) respectively form the first drainage channel (640) and the second drainage channel (740).

6. A dual-channel adaptive background subtraction Golay detector according to claim 4, characterized in that, The first absorption film layer (620) and the second absorption film layer (720) are both disposed on the bottom surface of the inner cavity of the first hollow cylinder (651) located above.

7. A dual-channel adaptive background subtraction Golay detector according to claim 1, characterized in that, The volume of the gas balance chamber (800) is greater than the volume of the first gas response chamber (650) and the volume of the second gas response chamber (750), respectively.

8. A dual-channel adaptive background subtraction Golay detector according to claim 4, characterized in that, A base plate (400) is provided below the support ring; the gas-sealed space is composed of the base plate (400), two silicon substrates (300) and the window glass (100), and is filled with He gas or Xe gas.

9. A dual-channel adaptive background subtraction Golay detector according to claim 8, characterized in that, The lower surfaces of the first deformation film (630) and the second deformation film (730) are both coated with a metal film layer; the upper surface portion of the base plate (400) located below the first upper electrode (660) is coated with a metal film layer, serving as the first lower electrode (670); the upper surface portion of the base plate (400) located below the second upper electrode (760) is coated with a metal film layer, serving as the second lower electrode (770).

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