A fold-change pulse radiation detector and a method for generating a high amplitude signal thereof

Abstract

The application discloses a folded pulse radiation detector and a method for generating a high-amplitude signal, and solves the technical problem that the existing folded pulse radiation detector is difficult to simultaneously realize high intrinsic resolution and improve the amplitude of the optical signal; the folded pulse radiation detector comprises an n-channel laser for emitting n paths of probe light, and further comprises n sensor structures, n delay adjusters, a fiber combiner and a photodetector; the input ends of the n sensor structures are connected to the output ends of the n-channel laser through optical fibers, and are used for converting the n paths of probe light into n beams of interference light and disturbing the interference light; the n delay adjusters are connected to the n sensor structures respectively, the input end of the fiber combiner is connected to the output ends of the n delay adjusters through optical fibers; and the photodetector is connected to the output end of the fiber combiner. Through the interference signal superposition mode, the amplitude response of the folded pulse radiation detector is improved while the high intrinsic time resolution is maintained.

Description

TECHNICAL FIELD

[0001] The present application relates to a pulse radiation detector and an optimization method thereof, in particular to a fold-change pulse radiation detector and a method for generating a high-amplitude signal. BACKGROUND

[0002] The short X / gamma-ray beam or electron beam generated by an advanced scientific device has strong penetrating ability and a duration of only tens of picoseconds. The pulse time waveform can be used to monitor the working state of the advanced scientific device and provide a reference for scientific experiments. The short electron beam can be measured based on transition radiation, electro-optic effect, space-time conversion, etc. It is difficult to measure the high-energy short X / gamma-ray beam due to low energy deposition efficiency and electrical neutrality, which exceeds the time resolution capability of most X / gamma-ray detectors and is challenging.

[0003] The intrinsic time resolution of the fold-change pulse radiation detector is only related to the time length of the process of generating excess carriers by ray photons. According to theoretical calculation, when a delta-ray pulse is incident, the time length of the process of generating excess carriers is mainly determined by the thickness of the material. The intrinsic time resolution capability of a thin material with a thickness of 300 microns can reach 3.3 picoseconds. Therefore, the fold-change pulse radiation detector using a thin material has high intrinsic time resolution, which is a competitive solution to the measurement of the time behavior of the ultra-short X / gamma-ray beam.

[0004] The fold-change pulse radiation detector using a thin material has the disadvantage of low sensitivity. It is difficult to achieve effective signal output with only a 300-micron-thick material. Although a thicker material can improve the sensitivity of the detector, the intrinsic time resolution will also deteriorate. The intrinsic time resolution of a 10-mm-thick material is 33 picoseconds, which cannot achieve the measurement purpose. SUMMARY

[0005] The purpose of the present application is to solve the technical problem that the fold-change pulse radiation detector using a thin material is difficult to achieve high intrinsic resolution and high signal amplitude at the same time, and to provide a fold-change pulse radiation detector and a method for generating a high-amplitude signal.

[0006] In order to achieve the above purpose, the present application adopts the following technical solutions:

[0007] A fold-change pulse radiation detector comprises an n-channel laser for outputting n paths of probe light, and is characterized in that it further comprises n sensor structures, n delay adjusters, a fiber combiner, and a photodetector, wherein n is greater than or equal to 2.

[0008] The input ends of the n sensor structures are respectively connected to the output ends of the n-channel laser through optical fibers, for converting the n paths of probe light into n beams of interference light respectively.

[0009] The n delay adjusters are respectively connected to the output ends of the n sensor structures, for adjusting the delay amount output by the corresponding sensor structure.

[0010] The input end of the optical fiber combiner is respectively connected to the output end of the n delay adjusters through optical fibers, for coupling the output results of the n delay adjusters to obtain combined light.

[0011] The photodetector is connected to the output end of the optical fiber combiner, for detecting the combined light output by the optical fiber combiner to obtain the time waveform of the to-be-detected radiation pulse, i.e., a high-amplitude signal.

[0012] Further, each sensor structure comprises an optical fiber circulator, a semiconductor wafer, and a single-mode optical fiber a; the input end of the optical fiber circulator is connected to one output end of the n-channel laser through an optical fiber, the output end of the optical fiber circulator is connected to one end of the single-mode optical fiber a, and the other end of the single-mode optical fiber a is connected to the input end of the delay adjuster.

[0013] One side of the semiconductor wafer is a sensitive area for receiving a radiation pulse, and the other side is connected to the isolation end of the optical fiber circulator through an optical fiber.

[0014] Further, the n paths of probe light output by the n-channel laser are direct current, tunable, and narrow-band near-infrared probe light, and the wavelength and power of the n paths of probe light can be adjusted individually.

[0015] Further, the sensitive areas of the n semiconductor wafers are staggered in the horizontal direction.

[0016] Further, the maximum adjustment time of each delay adjuster is greater than or equal to the maximum time difference of the signals generated by the n sensor structures and reaching the photodetector due to the radiation pulse.

[0017] Further, the optical fiber between the input end of the sensor structure and the output end of the n-channel laser is a single-mode optical fiber b.

[0018] Further, the radiation pulse is a single X / γ-ray pulse.

[0019] A method for generating a high-amplitude signal by a fold-change type pulse radiation detector, which is characterized by comprising the following steps:

[0020] Step 1: Adjust the optical path lengths of the n paths of probe light to be consistent through optical fiber length adjustment, to complete the coarse adjustment of the optical path.

[0021] Step 2, near-infrared femtosecond or picosecond laser pulses are used as timing radiation pulses, which are incident on the sensitive area of each sensor structure, and the time when each timing radiation pulse is received by the photodetector is recorded respectively;

[0022] Step 3, the time when each timing radiation pulse is received by the photodetector is combined to adjust the delay adjuster respectively, so that the time when each timing radiation pulse reaches the photodetector is consistent;

[0023] Step 4, n-channel lasers are turned on to output n paths of probe light, and the parameters of each path of probe light are adjusted, and the probe light generates interference light in the corresponding sensor structure;

[0024] Step 5, the sensitive areas of the n sensor structures are placed in the cross section of the to-be-measured radiation pulse, and the to-be-measured radiation pulse disturbs the interference light in the n sensor structures and transmits to the fiber combiner for beam combination to obtain combined light, and the combined light is incident on the photodetector to obtain the time waveform of the to-be-measured radiation pulse, that is, a high amplitude signal.

[0025] Further, in step 4, the adjustment of the parameters of each path of probe light specifically refers to the adjustment of the output intensity and wavelength of each path of probe light.

[0026] The beneficial effects of the present application are as follows:

[0027] 1. The folded pulse radiation detector and the method for generating a high amplitude signal thereof can improve the amplitude response of the folded pulse radiation detector by means of interference signal superposition while maintaining high intrinsic time resolution, and provide the possibility for the folded pulse radiation detector to realize ultra-short X / γ-ray pulse measurement.

[0028] 2. The folded pulse radiation detector can be used for high timing accuracy ray pulse arrival time measurement and monitoring. BRIEF DESCRIPTION OF DRAWINGS

[0029] Figure 1 It is a structural schematic diagram of an embodiment of the folded pulse radiation detector of the present application.

[0030] Figure 2 It is a structural schematic diagram of a sensor in an embodiment of the folded pulse radiation detector of the present application.

[0031] In the figure, 1-n channel lasers; 2-sensor structure, 201-fiber circulator, 202-semiconductor wafer, 203-single mode optical fiber a; 3-delay adjuster; 4-fiber combiner; 5-photodetector. DETAILED DESCRIPTION

[0032] The technical solution of the present invention will be clearly and completely described below with reference to the accompanying drawings and embodiments. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0033] like Figure 1 As shown, this embodiment of a refracted pulsed radiation detector includes an n-channel laser 1, n sensor structures 2, n delay modulators 3, an optical fiber combiner 4, and a photodetector 5, where n ≥ 2;

[0034] In this embodiment, the n-channel laser 1 is used to output n DC, tunable, narrowband near-infrared probe lights, and the wavelength and power of the n probe lights can be adjusted independently without affecting each other.

[0035] The n-sensor structure 2 includes an optical fiber circulator 201, a semiconductor wafer 202, and a single-mode optical fiber a 203. The input end of the optical fiber circulator 201 is connected to one output end of the n-channel laser 1 via a single-mode optical fiber b. The output end of the optical fiber circulator 201 is connected to one end of the single-mode optical fiber a 203, and the other end of the single-mode optical fiber a 203 is connected to a delay modulator 3. One side of the semiconductor wafer 202 is a sensitive area used to receive radiation pulses (which can be a single near-infrared femtosecond or a single picosecond laser pulse, or a short X / γ-ray beam or an electric current). The single-mode fiber a203 of each of the n sensor structures 2 is connected to the isolation end of the fiber optic circulator 201 via an optical fiber on the other side; the single-mode fiber a203 of each of the n sensor structures 2 is connected to the input end of the fiber optic combiner 4 via a delay regulator 3; the fiber optic circulator 201, semiconductor wafer 202, and single-mode fiber a203 in the n sensor structures 2 have the same material type, thickness, and surface treatment, and the operating wavelength variation range between each structure is less than one cycle, so as to minimize the influence of wavelength differences in refractive index response, and the detection area of ​​each structure is located at the center of the X-ray channel.

[0036] The probe light output from the n-channel laser 1 enters the fiber optic circulator 201 through the input end. After passing through the isolation end, part of it is reflected by the surface of the semiconductor wafer 202 and enters the fiber optic circulator 201, while the rest is transmitted into the semiconductor wafer 202. After being reflected by the other side of the semiconductor wafer 202, it enters the fiber optic circulator 201. The reflected light and the transmitted light interfere with each other in the fiber optic circulator 201, forming interference light.

[0037] In this embodiment, the timing radiation pulse is a single near-infrared femtosecond or a single picosecond laser pulse.

[0038] In the embodiment, the wavelength of the probe light is the same as that of the timing radiation pulse, the sensitive areas of the n semiconductor wafers 202 are staggered in the horizontal direction and are distributed in the cross section of the radiation pulse, and the probe light can enter the sensitive areas of different semiconductor wafers 201 when the radiation pulse is emitted.

[0039] In the embodiment, the single-mode optical fiber a 203 is connected to the time delay adjuster 3, the time delay of the optical signal in the optical fiber channel can be adjusted in a certain range by applying different voltages, the time when the signal pulse enters the photodetector 5 is controlled, and the signal light pulses of the channels are simultaneously sent to the photodetector 5 to superimpose the signal light pulse intensities.

[0040] In the embodiment, the input end of the optical fiber combiner 4 is connected to the output ends of the n time delay adjusters 3 through optical fibers, and is used to combine the n beams of the time-adjusted light to obtain the combined light. The optical fiber combiner 4 adopts an optical fiber combiner with high ray transmittance and small scattering, so that the rays also have considerable intensity at the rear end and generate effective superimposed signals.

[0041] In the embodiment, the maximum adjustment time of each time delay adjuster 3 is greater than or equal to the maximum time difference of the signals generated by the n-channel sensor structure under the disturbance of the to-be-measured radiation pulse and reaching the photodetector.

[0042] In the embodiment, the n-channel laser 1, the one sensor structure 2, and the one time delay adjuster 3 are taken as one interference optical path assembly; one interference optical path is generated, and the interference optical path is combined into one beam of high-amplitude signal in the optical fiber combiner 4 under the disturbance of the radiation pulse.

[0043] In the embodiment, the photodetector 5 is connected to the output end of the optical fiber combiner 4, and is used to detect the combined light output by the optical fiber combiner 4 to obtain the time waveform of the to-be-measured radiation pulse, that is, the high-amplitude signal.

[0044] The embodiment also provides a method for generating a high-amplitude signal by a fold-change type pulse radiation detector, which includes two parts of coarse adjustment and fine adjustment; wherein the coarse adjustment of the optical paths is completed by controlling the optical path and the length of the optical fiber. The sensor structure 2 uses the same model of optical fiber circulator 201, semiconductor wafer 202, and single-mode optical fiber a 203, the speed of the radiation pulse passing between the semiconductor wafers of the sensor structure 2 is calculated according to the speed of light in air, for a certain channel of the sensor structure 2, after the time delay adjuster is adjusted to the appropriate time delay value, the time for the disturbance signal generated by the radiation pulse to be transmitted from the rear surface of the semiconductor wafer to the photodetector remains the same, and the time difference of each channel is not greater than the maximum adjustment range of the time delay adjuster 3 before the time delay adjuster is adjusted.

[0045] The embodiment of the fold-change type pulse radiation detector for generating a high-amplitude signal specifically includes the following steps:

[0046] Step 1, the optical path of n probe lights is adjusted to be consistent through the length of the optical fiber, and coarse adjustment of the optical path is completed;

[0047] Step 2, a near-infrared femtosecond or picosecond laser pulse is used as a timing laser pulse, the timing laser pulse can fully cover the sensitive areas of the n sensor structures 2, the wavelength of the timing laser pulse is equal to the wavelength of the probe light, the timing laser pulse is incident on the photodetector from the first sensor structure 2, and the sensitive areas of each sensor structure 2 are respectively incident, and the time when each channel of the timing radiation pulse is received on the photodetector 5 is recorded;

[0048] In this embodiment, a single near-infrared femtosecond or picosecond laser pulse is used to be incident on the sensitive areas of each channel of the sensor structure 2, which can maintain high timing accuracy, and by adjusting the delay adjuster 3 of each channel, the arrival time of each channel of the probe light is combined as expected, the delay adjustment is completed, and this state is maintained during normal testing.

[0049] Step 3, the delay adjuster 3 is adjusted according to the time when each channel of the timing radiation pulse is received on the photodetector 5, so that the time when each channel of the timing radiation pulse reaches the photodetector 5 is consistent;

[0050] Step 4, the n-channel laser 1 outputs n channels of probe light, and the parameters of each channel of the probe light are adjusted, the probe light generates interference light in the corresponding sensor structure 2;

[0051] Step 5, the sensitive areas of the n sensor structures 2 are placed in the cross section of the to-be-measured radiation pulse, the to-be-measured radiation pulse disturbs the interference light in the n sensor structures 2, and transmits to the optical fiber combiner 4 for beam combination to obtain combined light, the combined light is incident on the photodetector 5, and the time waveform of the to-be-measured radiation pulse, i.e. a high amplitude signal, is obtained.

[0052] In the pulse radiation detector and the method for generating a high amplitude signal in the embodiment, high intrinsic time resolution and high response can be simultaneously achieved, which provides a solution for measuring ultrashort X / γ-ray pulses, and can also be used for measuring and monitoring the arrival time of a high timing accuracy radiation pulse.

[0053] The above is only a specific embodiment of the present application, and the effect of the related specific embodiment and the comparative example is compared, but the protection scope of the present application is not limited to this, any change or replacement within the technical scope disclosed in the present application should be covered within the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

Claims

1. A refractive pulsed radiation detector, comprising an n-channel laser (1), said n-channel laser (1) being used to output n probe beams; characterized in that: It also includes n sensor structures (2), n delay regulators (3), fiber optic combiners (4), and photodetectors (5), where n≥2; The n-channel laser (1) outputs n probe lights that are DC, tunable, and narrowband near-infrared probe lights, and the wavelength and power of the n probe lights can be adjusted individually. The input ends of n sensor structures (2) are respectively connected to the output ends of n-channel lasers (1) through optical fibers, which are used to convert n probe lights into n interference lights respectively. Sensitive areas are set on the n sensor structures (2) respectively, which are used to receive radiation pulses that cause disturbance to the interference light. The n delay regulators (3) are respectively connected to the output terminals of the n sensor structures (2) to adjust the delay amount of the output of the corresponding sensor structure (2); the maximum adjustment time of each delay regulator (3) is greater than or equal to the maximum time difference between the radiation pulse causing the signals generated by the n sensor structures (2) to reach the photodetector. The input end of the fiber optic combiner (4) is connected to the output ends of the n delay modulators (3) via optical fibers, which is used to couple the output results of the n delay modulators (3) to obtain a combined beam. The photodetector (5) is connected to the output end of the fiber optic combiner (4) and is used to detect the combined light output by the fiber optic combiner (4) to obtain the time waveform of the radiation pulse to be measured, i.e., the high amplitude signal.

2. The refracting pulse radiation detector according to claim 1, characterized in that: Each of the sensor structures (2) includes an optical fiber circulator (201), a semiconductor wafer (202), and a single-mode optical fiber a (203); the input end of the optical fiber circulator (201) is connected to one output end of an n-channel laser (1) via an optical fiber, the output end of the optical fiber circulator (201) is connected to one end of the single-mode optical fiber a (203), and the other end of the single-mode optical fiber a (203) is connected to the input end of a delay modulator (3); One side of the semiconductor wafer (202) is a sensitive area for receiving radiation pulses, and the other side is connected to the isolation end of the fiber optic circulator (201) via an optical fiber.

3. The refracting pulse radiation detector according to claim 1, characterized in that: The sensitive areas of n semiconductor wafers (202) are staggered in the horizontal direction.

4. The refracting pulse radiation detector according to claim 1, characterized in that: The optical fiber between the input end of the sensor structure (2) and the output end of the n-channel laser (1) is a single-mode optical fiber b.

5. A refracting pulse radiation detector according to claim 1, characterized in that: The radiation pulse is a single X / γ ray pulse.

6. A method for generating a high-amplitude signal based on any one of the refracted pulse radiation detectors described in claims 1-5, characterized in that, Includes the following steps: Step 1: Adjust the optical path length of the n probe beams to be consistent through the fiber optic cables to complete the coarse adjustment of the optical path. Step 2: Use near-infrared femtosecond or picosecond laser pulses as timing radiation pulses, respectively incident on the sensitive area of ​​each sensor structure (2), and record the time for each timing radiation pulse received on the photodetector (5); Step 3: Adjust the delay regulator (3) according to the time of each timed radiation pulse received on the photodetector (5) so that the time of each timed radiation pulse arriving at the photodetector (5) is consistent. Step 4: Turn on the n-channel laser (1) to output n probe beams, and adjust the parameters of each probe beam. The probe beams interfere with each other in the corresponding sensor structure (2) to generate interference light. Step 5: The sensitive areas of the n sensor structures (2) are misaligned and placed within the cross section of the radiation pulse to be measured. The radiation pulse to be measured disturbs the interference light in the n sensor structures (2) respectively, and is transmitted to the fiber optic combiner (4) for beam combining to obtain beam combined light. The beam combined light is incident on the photodetector (5) to obtain the time waveform of the radiation pulse to be measured, i.e., the high amplitude signal.

7. The method for generating high-amplitude signals using a refracting pulse radiation detector according to claim 6, characterized in that: In step 4, adjusting the parameters of each probe light specifically refers to adjusting the output intensity and wavelength of each probe light.

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