Photon counting measurement device

Abstract

Provided is a photon counting measurement device that reliably selects an available frequency band in an optical signal to be detected, prevents distortion due to overheating of a silicon photomultiplier tube, and improves the stability and accuracy of optical signal detection. 【Solution means】The photon counting measurement device includes a photosensitive element, a silicon photomultiplier tube, and a measurement control panel. A filter is provided in the silicon photomultiplier tube, a heat sink is attached to the bottom of the silicon photomultiplier tube, the photosensitive element receives an optical signal to be detected from a light source, the filter selects the optical signal to be detected by frequency band, and the silicon photomultiplier tube converts the selected optical signal into an electrical signal and transmits it to the measurement control panel. The measurement control panel performs amplification and filtering processing on the electrical signal to obtain a measurement digital signal, and the heat sink performs heat dissipation processing on the silicon photomultiplier tube. The present invention can realize remote data transmission and monitoring in combination with wireless communication counting.

Description

Technical Field

[0001] The present invention relates to the technical field of detecting weak optical signals, and particularly to a photon counting measurement device.

Background Art

[0002] Photon counting is a technique for detecting weak optical signals. A common method is to use a photomultiplier tube (PMT) as a receiver and detect the optical signal in the form of photoelectrons. When photons enter the photodetector, electrons emitted from the photocathode of the multiplier tube move to the anode under the action of the electric field in the tube, and photoelectron pulses appear on the load resistor of the anode. Subsequently, through processing, the optical signal is extracted from the noise in a digital manner. Since weak radiation signals are a flow of temporally discrete photons, the detector naturally outputs discrete electrical signals, and the use of pulse amplification, pulse discrimination, and counting techniques can effectively improve the sensitivity of weak light detection. Conventional photomultiplier tubes have the advantages of optical signal processing and amplification, but they are large in size, low in mechanical robustness, susceptible to the effects of magnetic fields, temperature, and aging of the equipment, and have strict requirements for the measurement environment, making it difficult to be put into practical use.

[0003] In existing research, a silicon photomultiplier (SiPM) is a new type of high-performance semiconductor photodetector composed of an array of multiple pixels operating in Geiger mode connected in parallel. Each pixel requires an avalanche photodiode and a quenching resistor connected in series. The silicon photomultiplier has characteristics such as a spectral response range from near ultraviolet to near infrared, excellent photon counting ability, single-photon level sensitivity, picosecond high-speed response ability, excellent time resolution, and high photon detection efficiency. Since it is a solid-state detector, it is not affected by magnetic fields, can withstand high-intensity mechanical impacts, and is not degraded by the saturation of incident light.

[0004] The fine feature sizes achievable by modern silicon microfabrication processes enable the realization of micrometer-sized PN junctions and anode / cathode regions. In combination with the high conductivity of doped silicon, it is possible to form a strong electric field (E-field) intensity within the depletion layer of a silicon detector. This enables silicon photodetectors to operate at low voltage and low supply current, reducing power consumption.

[0005] Current photon counters are based on silicon photomultipliers with additional signal output circuits. These have broad application value in industries such as scientific research institutions, the solar power generation industry, and cell analysis. However, currently, they are mainly used for qualitative analysis in laboratory research, lacking more detailed quantitative analysis of optical signals, not being applied to on-site instrument meters, not contributing to real-time remote data monitoring, and furthermore, during actual use, the optical signals to be detected often have multiple bands, so interference is likely to occur during detection, and silicon photomultipliers are prone to overheating distortion, reducing the stability and accuracy of optical signal processing.

Summary of the Invention

Problems to be Solved by the Invention

[0006] The object of the present invention is to overcome the above-mentioned drawbacks of the prior art, reliably select the available frequency bands in the optical signal to be detected, prevent distortion due to overheating of the silicon photomultiplier, and provide a photon counting measurement device capable of improving the stability and accuracy of optical signal detection.

[0007] The object of the present invention can be achieved by the following technical solutions. A photon counting measurement device includes a photosensitive element, a silicon photomultiplier tube, and a measurement control panel. A filter is provided in the silicon photomultiplier tube, a heat sink is attached to the bottom of the silicon photomultiplier tube, the photosensitive element receives an optical signal of a detection target from a light source, the filter selects the optical signal of the detection target by frequency band, the silicon photomultiplier tube converts the selected optical signal into an electrical signal and transmits it to the measurement control panel, the measurement control panel amplifies and filters the electrical signal to obtain a measurement digital signal, and the heat sink performs heat dissipation treatment on the silicon photomultiplier tube.

[0008] Furthermore, a comparison amplifier and a filtering and shaping device are provided in the measurement control panel.

[0009] Furthermore, the photosensitive element, the silicon photomultiplier tube, and the measurement control panel are all mounted in an instrument housing.

[0010] Furthermore, an instrument panel is provided on the instrument housing, the instrument panel is connected to the measurement control panel, and is used to display the current measurement data accordingly.

[0011] Furthermore, the instrument panel and the measurement control panel are connected by a hard wire.

[0012] Furthermore, a wireless communication module is arranged in the instrument housing, the wireless communication module is communicatively connected to a user terminal, and is used to transmit the current measurement data to the user terminal in real time.

[0013] Furthermore, the wireless communication module is configured to connect an output module to the instrument panel, so as to obtain the current measurement data transferred from the instrument panel.

[0014] Furthermore, the user terminal is specifically a computer, a mobile phone, or a tablet computer.

[0015] Furthermore, the optical filter is disposed in a replaceable and detachable manner with respect to the silicon photomultiplier tube.

[0016] Compared with the prior art, the present invention has the following advantages.

[0017] In the present invention, a filter is disposed on a silicon photomultiplier tube, a heat sink is attached to the bottom of the silicon photomultiplier tube, an optical signal of a detection target is selected by frequency band using the filter, and heat dissipation processing is performed on the silicon photomultiplier tube using the heat sink. Thereby, an available frequency band can be effectively selected, mutual interference between a plurality of frequency bands can be reduced, overheating distortion of the silicon photomultiplier tube can be prevented, and a stable optical signal processing function can be maintained.

[0018] In the present invention, a photosensitive element, a silicon photomultiplier tube, and a measurement control panel are attached in an instrument housing, an instrument panel is disposed on the instrument housing, the instrument panel and the measurement control panel are connected, and current measurement data is displayed, thereby realizing a specific application of on-site instruments and meters.

[0019] In the present invention, a comparison amplifier and a filtering and shaping device are disposed on the measurement control panel to further amplify a signal and perform filtering processing to reduce an interference signal and ensure the accuracy of a measurement result.

[0020] In the present invention, a wireless communication module is disposed in the instrument housing, and the wireless communication module is communicatively connected to a user terminal, thereby transmitting current measurement data to the user side in real time and realizing a data remote transmission function contributing to remote monitoring.

Brief Description of the Drawings

[0021]

Figure 1

Figure 2

Description of the Reference Numerals

[0022] 1. Light source, 2. Photosensitive element, 3. Filter, 4. Silicon photomultiplier tube, 5. Measurement control panel, 6. Instrument panel, 7. Instrument housing, 8. User terminal.

Embodiment for Carrying out the Invention

[0023] Hereinafter, the present invention will be described in detail in conjunction with the accompanying drawings and specific embodiments.

Example

[0024] As shown in FIG. 1, a photon counting measurement device includes a photosensitive element 2, a silicon photomultiplier tube 4, and a measurement control panel 5. A filter 3 is disposed on the silicon photomultiplier tube 4, a heat sink is attached to the bottom of the silicon photomultiplier tube 4, the photosensitive element 2 receives an optical signal of a detection target from the light source 1, the filter 3 selects the optical signal of the detection target by frequency band, and the silicon photomultiplier tube 4 is provided in a replaceable and removable manner, that is, by replacing different filters, selection of optical signals of different frequency bands of the same light source can be realized. The silicon photomultiplier tube 4 converts the selected optical signal into an electrical signal and transmits it to the measurement control panel 5. The measurement control panel 5 amplifies and filters the electrical signal to obtain a measurement digital signal. The heat sink performs a heat dissipation process on the silicon photomultiplier tube 4.

[0025] Specifically, the measurement control panel 5 is provided with a comparison amplifier and a filtering and shaping device.

[0026] The photosensitive element 2, the silicon photomultiplier tube 4, and the measurement control panel 5 are all mounted in the instrument housing 7. The instrument housing 7 is provided with an instrument panel 6. The instrument panel 6 is connected to the measurement control panel 5 (in this embodiment, the instrument panel 6 and the measurement control panel 5 are connected by a hard wire) and correspondingly displays the current measurement data. A wireless communication module is further arranged inside the instrument housing 7. The wireless communication module is communicatively connected to the user terminal 8 and is used to transmit the current measurement data to the user terminal 8 in real time. The wireless communication module obtains the current measurement data transferred from the instrument panel 6 by arranging an output module connected to the instrument panel 6.

[0027] During actual use, the user terminal 8 is specifically a computer, a mobile phone, or a tablet computer.

[0028] Based on the above device, as shown in FIG. 2, a photon counting measurement method is realized. The method includes: Step S1: The photosensitive element receives the optical signal of the detection target from the light source and transmits it to the silicon photomultiplier tube. Step S2: The filter on the silicon photomultiplier tube selects the frequency band of the optical signal of the detection target, obtains the selected optical signal. Then, the silicon photomultiplier tube converts the selected optical signal into a corresponding electrical signal and transmits it to the measurement control panel. Step S3: The measurement control panel amplifies and filters the electrical signal to obtain a measurement digital signal, that is, a measurement result.

[0029] As can be seen from the above, in this solution, a photosensitive element is used to receive a light source, the received optical signal is transmitted to a silicon photomultiplier tube, a filter is provided in the silicon photomultiplier tube, and by exchanging different filters, optical signals in different frequency bands of the same light source can be selected. The selected optical signal is converted into an electrical signal by the silicon photomultiplier tube, and the electrical signal is output to a measurement control panel. In order to prevent the silicon photomultiplier tube from overheating during long-term photoelectric conversion, a heat sink can be used to immediately dissipate heat. The measurement control panel uses a provided preamplifier and a filtering and shaping device to amplify the electrical signal converted from a weak electrical signal, perform filtering processing to reduce interference signals, and finally output a digital signal to a digital instrument through a hard wire for display. All of the above functions are designed inside the instrument housing and can also be displayed on a remote user terminal using wireless remote transmission technology.

[0030] This solution has the following advantages. 1. It has low power consumption and is small in size. Conventional photomultiplier measurement devices are large in size, low in mechanical robustness, and high in power consumption, so the usage cost is high. This device has a compact design structure, the power consumption requirement is reduced, and the cost is reduced while ensuring functionality. 2. Reduce the complexity of optical signal processing. This mainly involves the processing of noise signals. For example, it is the dynamic range such as interference signals superimposed on useful signals. The dynamic range refers to the range of optical signal levels within which a detector can provide an effective output. In the case of a silicon photomultiplier (SiPM), the dynamic range is the range from the minimum detectable optical signal level to the optical signal level at which all pixels detect photons simultaneously. When all pixels detect photons simultaneously, the output signal of the silicon photomultiplier (SiPM) saturates, that is, there are no more pixels available to detect other incident photons until some micropixels return to the detectable stage. Therefore, the dynamic range of the silicon photomultiplier (SiPM) is a function of the total number of pixels and the detection efficiency. At the same time, since the detection efficiency is related to the bias voltage and the wavelength of the incident light, the dynamic range of the silicon photomultiplier (SiPM) is also a function of the bias voltage and the wavelength. When the number of incident photons per unit time is much less than the number of pixels, the response of the silicon photomultiplier (SiPM) is linear. As the number of incident photons per unit time increases, the response of the silicon photomultiplier (SiPM) tends to saturate gradually. That is, at low optical signal levels, the output photocurrent of the silicon photomultiplier (SiPM) has a positive correlation with the incident optical power. As the incident optical power increases, due to the limitation of the number of pixels of the silicon photomultiplier (SiPM), its output photocurrent begins to deviate from the linear response region and finally saturates. 3. Enhance the filtering effect, strictly limit the frequency band of the selected light rays, and reduce optical crosstalk. Due to the complexity of optical signal measurement, the ratio of the number of secondary photons detected by a silicon photomultiplier (SiPM) to the number of incident photons detected is the optical crosstalk probability of the silicon photomultiplier (SiPM). 4. Add a heat dissipation device. More heat is generated by the photoelectric effect, and the measurement temperature can be rapidly reduced by the heat dissipation device. Temperature is also an important factor affecting the silicon photomultiplier (SiPM), which ensures the accuracy of the measurement. 5. Arrange an output module connectable to the control system. Ensure that the measurement range meets the accuracy requirements. When used in combination with the remote transmission communication module, it is possible to read information from the photon counting measurement device, and the system design can be further improved and optimized. 6. Instead of wasting time researching advanced theories in the laboratory, arrange a standard instrument housing for on-site installation and customize the product using its physical characteristics.

Claims

1. A photon counting measurement device, comprising a photosensitive element (2), a silicon photomultiplier tube (4), and a measurement control panel (5). A filter (3) is provided in the silicon photomultiplier tube (4), and a heat sink is attached to the bottom of the silicon photomultiplier tube (4). The photosensitive element (2) is used to receive an optical signal of a detection target from a light source (1), the filter (3) is used to select the optical signal of the detection target by frequency band, the silicon photomultiplier tube (4) is used to convert the selected optical signal into an electrical signal and transmit it to the measurement control panel (5), the measurement control panel (5) is used to perform amplification and filtering processing on the electrical signal to obtain a measurement digital signal, and the heat sink is used to perform a heat dissipation process on the silicon photomultiplier tube (4). A photon counting measurement device characterized by the above.

2. The photon counting measurement device according to claim 1, characterized in that a comparison amplifier and a filtering and shaping device are provided in the measurement control panel (5).

3. The photon counting measurement device according to claim 1, characterized in that the photosensitive element (2), the silicon photomultiplier tube (4), and the measurement control panel (5) are all mounted in an instrument housing (7).

4. The photon counting measurement device according to claim 3, characterized in that an instrument panel (6) is provided on the instrument housing (7), the instrument panel (6) is connected to the measurement control panel (5), and is used to display current measurement data accordingly.

5. The photon counting measurement device according to claim 4, characterized in that the instrument panel (6) and the measurement control panel (5) are connected by a hard wire.

6. The photon counting measurement device according to claim 4, characterized in that a wireless communication module is provided in the instrument housing (7), the wireless communication module is communicatively connected to a user terminal (8), and is used to transmit current measurement data to the user terminal (8) in real time.

7. The photon counting measurement device according to claim 6, characterized in that the wireless communication module is configured to connect an output module to the instrument panel (6) to obtain current measurement data transferred from the instrument panel (6).

8. The photon counting measurement device according to claim 6, wherein the user terminal (8) is specifically a computer, a mobile phone, or a tablet computer.

9. The photon counting measurement device according to any one of claims 1 to 8, wherein the filter (3) is arranged to be replaceable and detachable from the silicon photomultiplier tube (4).

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