CN115863137A - A high time resolution photomultiplier tube and its realization method - Google Patents

Abstract

The invention provides a high-time-resolution photomultiplier and a realization method thereof, and mainly solves the technical problems that in the electron multiplication process of the conventional photomultiplier, the transit time dispersion causes that electron pulses with smaller pulse widths generate pulse width broadening of multiple times after electron multiplication, so that detection results generate detection distortion compared with original signals, or two beams of electron pulses with short interval time overlap with the back edge part of the former pulse in the multiplication process, and finally the time and intensity information of the two pulses are difficult to identify due to the same output at an anode, thereby influencing the time resolution of the photomultiplier. The electron multiplier comprises N readout electrodes, a cathode, an electron multiplier, N gating electrodes and N anodes, wherein the cathode, the electron multiplier, the N gating electrodes and the N anodes are arranged in a vacuum environment, and N is an integer larger than 1.

Description

A high time resolution photomultiplier tube and its realization method

technical field

The invention relates to a photomultiplier tube and a realization method thereof, in particular to a photomultiplier tube with high time resolution and a method for realizing photomultiplier with high time resolution.

Background technique

Lidar is an emerging detection device, because of its high resolution, strong anti-interference, small size, and light weight, it is widely used in national security protection, scientific research, environmental monitoring and other fields. The main working principle of lidar is to transmit detection light signals to the detection target, and then use the photoelectric imaging device or photodetection device to collect and detect the light signal reflected from the target, and then obtain the distance of the detected target after proper processing. Relevant information such as shape, orientation, speed, etc.; as the core component of lidar, the performance of the photodetector directly affects the parameters of the lidar system, for example: the photoelectric detection efficiency of the photodetector device directly affects the effective detection distance of the lidar The time resolution of the detection device directly affects the detection accuracy of the lidar; therefore, the photodetector used in the lidar system needs to have high photon detection efficiency and high time resolution characteristics, so as to have high gain and high time resolution.

The photodetectors in existing lidar systems usually use photomultiplier tubes. Among them, vacuum photomultiplier tubes are very suitable for long-distance and weak light due to their characteristics of large detection area, high electronic gain, small dark noise, and high time resolution. Signal, large field of view lidar system.

Although vacuum-type photomultiplier tubes are widely used in lidar systems, due to the limitation of their own working methods, vacuum-type photomultiplier tubes have the disadvantage of low limit time resolution; the electron multiplier devices of vacuum-type photomultiplier tubes mainly include Electrodes and microchannel plate electron multiplication devices, both electron multiplication devices achieve electron multiplication through continuous collision of electrons with the effective electron multiplication area of the device; but the initial energy and initial motion of the cathode exiting electrons and collision reflected electrons in the vacuum photomultiplier tube There are differences in the directions, coupled with the influence of the space charge effect in the electron multiplication region, the arrival time of the electron beam in the photomultiplier tube is also different during the movement to the anode, resulting in the dispersion of the transit time of the photomultiplier tube.

To sum up, the existing photomultiplier tubes have transit time dispersion in the process of electron multiplication, resulting in electron pulses with small pulse widths being multiplied by electrons to produce pulse widths that are several times wider, making the detection results more distorted than the original signal. , or during the multiplication process of two beams of electron pulses with a short interval, the trailing part of the previous pulse overlaps with the leading part of the following pulse, and finally the same output at the anode makes it difficult to identify the time and intensity information of the two pulses, This affects the time resolution of the photomultiplier tube.

Contents of the invention

The purpose of the present invention is to solve the problem that the existing photomultiplier tube has transit time dispersion in the process of electron multiplication, which causes the electronic pulse with a small pulse width to produce several times of pulse width expansion after electron multiplication, so that the detection result is higher than that of the original signal. Distortion, or during the multiplication process of two electron pulses with a short interval, the trailing edge of the previous pulse overlaps with the leading edge of the next pulse, and finally the same output at the anode makes it difficult to identify the time and intensity information of the two pulses , thereby affecting the technical problem of the time resolution of the photomultiplier tube, and providing a photomultiplier tube with high time resolution and a realization method.

To achieve the above object, the technical solution adopted in the present invention is:

A photomultiplier tube with high time resolution, which is special in that it includes N readout electrodes, cathodes, electron multipliers, N gate electrodes and N anodes arranged in a vacuum environment, and N is greater than 1 an integer of

The cathode and the electron multiplier are arranged in parallel with each other, and there is a first gap between them, and the range of the first gap is 0.5 mm to 5 mm;

The N gate electrodes are all arranged in the first gap, and are used to respectively apply gate pulses with different time parameters to control whether the electrons emitted by the cathode can enter the electron multiplier, and the total area of the N gate electrodes is equal to The effective area of the cathode, a second gap is set between one side of the gate electrode and the cathode, the second gap ranges from 0.2 mm to 1 mm, and a third gap is set between the other side and the electron multiplier. The range of three gaps is 0.3mm ~ 4mm;

The N anodes are all arranged on the side of the electron multiplier away from the cathode for collecting the electrons multiplied by the electron multiplier, and the N anodes are arranged in one-to-one correspondence with the N gate electrodes, and the anode and the electron multiplier A fourth gap is provided between the devices, and the range of the fourth gap is 1mm to 5mm;

One end of the N readout electrodes is respectively connected to the side of the N anodes away from the electron multiplier, and the other end is used to connect with an external device to output electrons collected by the anodes.

Further, the electron multiplier is an electron multiplier made of a secondary electron multiplying material.

Further, the electron multiplier is a microchannel plate electron multiplier, or a dynode electron multiplier.

Further, the cathode is an ultraviolet cathode, an infrared cathode or a visible light cathode;

The cathode is a thin plate structure, and N gate electrodes are arranged along the length direction of the cathode.

Further, the anode is in the shape of a sheet or a cone;

The interior of the gate electrode is a regular hexagonal network structure, and the shape of the gate electrode is the same as that of the anode.

Further, the readout electrode is a cable with fixed impedance.

Further, the readout electrodes are metal wires or coaxial cables.

At the same time, the present invention also provides a method for realizing photomultiplication with high time resolution, based on a photomultiplier tube with high time resolution, which is special in that it includes the following steps:

Step 1, applying fixed potentials of different sizes to the cathode, the gate electrode, the electron multiplier and the anode respectively;

A fixed voltage difference V _clo is formed between the gate electrode and the cathode, so that electrons emitted by the cathode cannot pass through the gate electrode; a fixed electron acceleration voltage difference V _ac is formed between the gate electrode and the electron multiplier, so that electrons passing through the gate electrode Electrons can enter the electron multiplier; a fixed electron acceleration voltage difference V _a is formed between the electron multiplier and the anode, so that the electrons multiplied by the electron multiplier can enter the anode;

Step 2, when performing optical signal detection, apply gate pulses with different time parameters to the N gate electrodes respectively, the gate pulses with different time parameters are: T _d of the pulse width of the N gate pulses is the same, and T The value range of _d is from 1 ps to 1 μs, the starting time of the rising edge of N strobe pulses is sequentially delayed on the time axis, and the starting time difference between the rising edges of two adjacent strobe pulses is Δt; or, N The starting time of the rising edge of the strobe pulse is the same, the pulse width of the N strobe pulses increases sequentially, and the pulse width difference between two adjacent strobe pulses is Δt; the value range of Δt is 1ps to 500ns;

The strobe pulses applied by two adjacent strobe electrodes have an overlapping time period, and the total time of the strobe pulse superposition applied by N strobe electrodes is greater than the duration of the optical signal to be detected, and the starting time of the rising edge is the earliest, Or the optical signal to be detected is not in a continuous state within the duration of the strobe pulse with the smallest pulse width;

The amplitude of the strobe pulse is V _g , V _g ≥ V _clo , so that the N strobe electrodes are in the strobe state during the positive pulse period of the corresponding strobe pulse;

Step 3, the anode outputs a detection waveform signal during the time period when the corresponding gate electrode is in the gate state and the light signal to be detected is in the continuation state;

Sorting the detection waveform signals according to the order of the rising edges of the corresponding gate pulses of the N gate electrodes on the time axis, or the order of the pulse width from short to long;

Step 4. Define the anode corresponding to the first strobe electrode or the strobe electrode with the shortest strobe time as the basic anode, and define the characteristic charge output of the detection waveform signals output by adjacent two anodes during the non-overlapping time period as Q _3. Calculate the characteristic charge Q ₃ output during the non-overlapping time period of the other anodes except the basic anode;

Integrate the detection waveform signal output by the latter anode among two adjacent anodes to obtain the total charge Q ₁ output by the anode, and integrate the detection waveform signal output by the previous anode to obtain the total charge Q output by the anode ₂ , Q ₃ =Q ₁ -Q ₂ ;

Step 5, carry out de-integration processing to obtain all characteristic electric charges Q ₃ respectively to obtain the characteristic waveform signal of corresponding anode, carry out fitting and reconstruction to all characteristic waveform signals obtained according to the timing information of different time parameter strobe pulses, obtain high time high-resolution detection waveforms.

Further, in step 1, V _clo <-5V, V _ac >10V, and V _a >10V.

Compared with prior art, the beneficial effect of the present invention is:

The present invention divides the photomultiplier tube into N regions by setting N gating electrodes, and each region can not only work independently, but also realize the gating detection function independently; at the same time, N gating electrodes can also work together to realize photoelectric N gating electrodes in the multiplier tube are cascaded to perform gating detection, which expands the function of a single device; by applying gating pulses with different time parameters to the N gating electrodes, the detection time of different gating electrodes is realized. Different, so that the intensity change information of the optical signal in a short time interval is output through the anode, and then the optical signal intensity change waveform with high time accuracy is inverted, which reduces the detection distortion of the detection result compared with the original signal, and improves the time of the photomultiplier tube. The resolution makes the limit time resolution of the photomultiplier tube reach the picosecond level.

Description of drawings

Fig. 1 is the structural representation of a kind of high time resolution photomultiplier tube of the present invention;

Fig. 2 is a schematic diagram of a method for realizing photomultiplication with high time resolution in the present invention;

Fig. 3 is the structural representation of photomultiplier tube in the embodiment 1 of the present invention;

Fig. 4 is a waveform diagram of a gate pulse in Embodiment 1 of the present invention;

Fig. 5 is a schematic diagram of the implementation process of photomultiplication with high time resolution in Embodiment 1 of the present invention;

Fig. 6 is a waveform diagram of a strobe pulse in Embodiment 2 of the present invention;

Fig. 7 is a schematic diagram of the implementation process of photomultiplication with high time resolution in Embodiment 2 of the present invention.

In the figure, 1-cathode, 2-electron multiplier, 3-gate electrode, 4-anode, 5-readout electrode.

Detailed ways

In order to make the purpose, advantages and features of the present invention clearer, a high-time-resolution photomultiplier tube proposed by the present invention and its implementation method will be further described in detail below in conjunction with the accompanying drawings and specific embodiments. The advantages and features of the present invention will be more clear from the following specific embodiments. It should be noted that: the drawings are all in a very simplified form and use inaccurate proportions, which are only used to facilitate and clearly illustrate the purpose of the embodiments of the present invention; secondly, the structures shown in the drawings are often actual structures part.

As shown in Figure 1, a high time resolution photomultiplier tube of the present invention includes N readout electrodes 5, and a cathode 1, an electron multiplier 2, N gate electrodes 3 and N For the anode 4, N is an integer greater than 1.

The cathode 1 and the electron multiplier 2 are arranged parallel to each other, and there is a first gap between them, and the range of the first gap is 0.5 mm to 5 mm; wherein the cathode 1 is an ultraviolet cathode, an infrared cathode or a visible light cathode, and has a thin plate structure; The electron multiplier 2 is a structure that realizes electron multiplication through a secondary electron multiplication material, specifically, the electron multiplier 2 is a microchannel plate electron multiplier, or a dynode electron multiplier;

The N gate electrodes 3 are all arranged in the first gap, and are used to apply gate pulses with different time parameters to control whether the electrons emitted by the cathode 1 can enter the electron multiplier 2, and the N gate electrodes 3 are arranged along the Arranged in the length direction, the total area of the N gate electrodes 3 is equal to the effective area of the cathode 1, and a second gap is provided between one side of the gate electrode 3 and the cathode 1, and the range of the second gap is 0.2 mm to 1 mm. A third gap is arranged between one side and the electron multiplier 2, and the range of the third gap is 0.3 mm to 4 mm; the inside of the gate electrode 3 is a metal part with a regular hexagonal mesh structure, and the shape of the gate electrode 3 It is the same shape as the anode 4 which will be described in detail below;

The N anodes 4 are all arranged on the side of the electron multiplier 2 away from the cathode 1, and are used to collect electrons multiplied by the electron multiplier 2. The N anodes 4 are arranged in one-to-one correspondence with the N gate electrodes 3. The shape of the anode 4 It is sheet-shaped or conical, and a fourth gap is provided between the anode 4 and the electron multiplier 2, and the range of the fourth gap is 1 mm to 5 mm;

One end of the N readout electrodes 5 is respectively connected to the side of the N anodes 4 away from the electron multiplier 2, and the other end is used to connect with external electrical appliances to output the electrons collected by the anode 4. The readout electrodes 5 are metal wires and coaxial cables. or a cable with a fixed impedance.

As shown in Fig. 2, a kind of realization method of high time resolution photomultiplier of the present invention, based on a kind of high time resolution photomultiplier tube, comprises the following steps:

Step 1, applying fixed potentials of different sizes to the cathode 1, the gate electrode 3, the electron multiplier 2 and the anode 4 respectively;

A fixed voltage difference V _clo is formed between the gate electrode 3 and the cathode 1, V _clo <-5V, so that the electrons emitted by the cathode 1 cannot pass through the gate electrode 3; a fixed electron is formed between the gate electrode 3 and the electron multiplier 2 Acceleration voltage difference V _ac , V _ac > 10V, so that the electrons passing through the gate electrode 3 can enter the electron multiplier 2; a fixed electron acceleration voltage difference V _a is formed between the electron multiplier 2 and the anode 4, V _a > 10V , so that the electrons multiplied by the electron multiplier 2 can enter the anode 4;

Step 2. When performing optical signal detection, respectively apply gate pulses with different time parameters to the N gate electrodes 3. Specifically, the gate pulses with different time parameters are: the pulse widths of the N gate pulses have the same Td, The value range of T _d is 1ps～1μs, the rising edge starting time of N strobe pulses is sequentially delayed on the time axis, and the starting time difference between the rising edges of two adjacent strobe pulses is Δt; or, N The starting time of the rising edge of each strobe pulse is the same, the pulse width of N strobe pulses increases sequentially, and the pulse width difference between two adjacent strobe pulses is Δt; the value range of Δt is 1ps～500ns;

The strobe pulses applied by two adjacent strobe electrodes 3 have an overlapping time period, and the total time of superposition of the strobe pulses applied by N strobe electrodes 3 is greater than the duration of the optical signal to be detected, and at the start time of the rising edge The optical signal to be detected is not in a continuous state during the duration of the strobe pulse with the earliest or smallest pulse width;

The amplitude of the gate pulse is V _g , V _g ≥ V _clo , so that the N gate electrodes 3 are in the gate state during the positive pulse period of the corresponding gate pulse;

Step 3, the anode 4 outputs a detection waveform signal during the time period when the corresponding gate electrode 3 is in the gate state and the light signal to be detected is in the continuation state;

Sorting the detection waveform signals according to the order of the rising edges of the corresponding gate pulses of the N gate electrodes 3 on the time axis, or the order of the pulse width from short to long;

Step 4. Define the anode 4 corresponding to the first strobe electrode 3 or the strobe electrode 3 with the shortest strobe time as the basic anode 4, and define the detection waveform signals output by two adjacent anodes 4 during the non-overlapping time period. The characteristic charge quantity is Q3, and the characteristic charge quantity Q3 output during the non-overlapping time period of the other anodes 4 except the basic anode 4 is calculated, specifically:

Integrate the detection waveform signal output by the latter anode 4 among two adjacent anodes 4 to obtain the total charge Q1 output by the anode 4, and integrate the detection waveform signal output by the previous anode 4 to obtain the total charge Q1 output by the anode 4 Total charge Q2, Q3=Q1-Q2;

Step 5. Perform inverse integration processing on all the obtained characteristic charge Q3 to obtain the characteristic waveform signal corresponding to the anode 4, and perform fitting and reconstruction on all the obtained characteristic waveform signals according to the timing information of the gate pulse with different time parameters to obtain the high time high-resolution detection waveforms.

Example 1

As shown in Figure 3, electron multiplier 2 selects microchannel plate electron multiplier 2 for use in the present embodiment, is made of two rectangular MCP boards (microchannel plate), and the quantity of gate electrode 3 and anode 4 is four , the distance between the cathode 1 and the gate electrode 3 is 0.4 mm, the distance between the gate electrode 3 and the input surface of the electron multiplier 2 is 1 mm, and the distance between the electron multiplier 2 and the anode 4 is 1 mm.

In this embodiment, the electron multiplier tube adopts a negative voltage working mode, the initial voltage of the gate electrode 3 is -2000V, the voltage of the cathode 1 is -1995V, the voltage of the input electrode of the electron multiplier 2 is -1800V, and the voltage of the output electrode of the electron multiplier 2 is -200V, at this time, the electrons emitted by the cathode 1 in the photomultiplier tube cannot pass through the gate electrode 3, and the photomultiplier tube is in the cut-off state, but the electron multiplier 2 is in a normal working state, and the electron multiplication function can be realized when there is electron input .

As shown in FIG. 4, when performing optical signal detection, electronic pulses with different time parameters are applied to the gate electrode 3, and the electronic pulses are defined as the first electronic pulse, the second electronic pulse, ..., the Nth electronic pulse, Correspondingly, the gate electrodes 3 are respectively the first gate electrode, the second gate electrode, ..., the Nth gate electrode, wherein the first pulse signal is applied to the first gate electrode, the second gate electrode, and the second gate electrode. The pulse signal is applied to the second strobe electrode, and so on, the Nth strobe pulse is applied to the Nth strobe electrode; in this embodiment, the amplitude of the strobe pulse is 10V, and all strobe pulses The starting time of each is the same, but the pulse width is incremented by 500ps.

As shown in Figure 5, when the photomultiplier tube of the present invention detects the optical signal, although the first gate pulse is applied to the first gate electrode, since there is no light signal irradiated on the gate pulse during the duration of the gate pulse Cathode 1, so the anode 4 corresponding to the first strobe electrode to which the strobe pulse is applied at this time has no detection signal waveform output; as the strobe pulse time goes on, when the second strobe pulse is applied to the second When the electrodes are selected, the first optical signal pulse appears within the time period covered by the second selection pulse. At this time, the second selection electrode corresponds to the anode 4 to output the corresponding detection signal waveform and record the corresponding waveform information, and calculate the waveform information Corresponding time information, intensity information, etc., and integrate the detection waveform to obtain the total output charge, which is the detection charge within 500ps (marked as t2 at the midpoint); then the third gate electrode applies the third Strobe pulse, in the time period covered by the strobe pulse, except for the first light signal pulse, the second light signal pulse has not yet appeared. At this time, the output waveform of the corresponding anode 4 and the total amount of charge are consistent with the total amount of charge output by the second anode 4. At this time, the total amount of charge output by the third anode 4 minus the total amount of charge output by the second anode can be used to obtain the detection charge amount in the second 500 ps (marked as t3 at the midpoint); then the fourth strobe electrode is applied The fourth strobe pulse, in addition to the first light signal pulse, the second light signal pulse appears in the time period covered by the strobe pulse. At this time, the total output charge of the fourth strobe electrode corresponding to the anode 4 also includes two The amount of charge corresponding to the light pulse signal, at this time, subtract the total output charge of the anode 4 corresponding to the third strobe electrode from the total output charge of the anode 4 corresponding to the fourth strobe electrode, and the third 500ps ( The midpoint is marked as t4) to detect the amount of charge; according to this detection method, the detected charge amount within 500 ps adjacent to each anode 4 can be calculated, and the charge amount information is de-integrated to obtain the corresponding characteristic waveform signal, and according to The sequence of time features Fitting and reconstructing the waveform signal can restore the high-precision time and intensity information of each detected light pulse, and realize the high-time-resolution detection function of the photomultiplier tube.

Since the time difference between two adjacent strobe pulses is 500ps, the time difference corresponding to the output signals of two adjacent anodes 4 is also 500ps, and the calculation of the output signals of adjacent anodes 4 can be obtained when the optical signal is at a time interval of 500ps Intensity variation trend, thus time The time resolution of this photomultiplier tube reaches 500ps. If the value of Δt is chosen to be smaller, reaching the level of picoseconds, the limit time resolution of the high time resolution photomultiplier tube of the present invention can reach the level of picoseconds.

Example 2

In this implementation case, the structure of the photomultiplier tube, the way of applying the working voltage and the numerical value are all the same as those of the implementation case 1.

As shown in Figure 6, the first pulse signal is applied to the first gate electrode, the second pulse signal is applied to the second gate electrode, and so on, the Nth gate pulse is applied to the Nth gate electrode. on the electrode. In this embodiment, the amplitude of the gate pulse is 10V, the width Td of all gate pulses is 10 ns, and the start time difference between two adjacent pulses is Δt, and the value of Δt is 500 ps.

As shown in Figure 7, the specific detection process of this embodiment is the same as that of Embodiment 1, but when performing waveform processing between each anode 4, use the third strobe electrode to correspond to the total amount of detection charge output by the anode and the second The total amount of detected charge output by the anode corresponding to the first gate electrode is integrated within the overlapped time period to perform subtraction processing, and the detected charge amount of the anode output signal corresponding to the third gate electrode in the last 500 ps can be obtained. The detection charge amount of the other anode 4 within the last 500 ps can be obtained. The characteristic waveform signal is obtained by de-integrating the detected charge information. The characteristic waveform signal is fitted and reconstructed according to the sequence of time to restore the high-precision time and intensity information of each detected light pulse, realizing the high-time photomultiplier tube. Resolution detection function. Similarly, if the value of Δt is selected to be smaller and reaches the picosecond level, the limit time resolution of the high time resolution photomultiplier tube of the present invention can also reach the picosecond level.

Claims (9)

1. A high temporal resolution photomultiplier tube characterized by: the electron multiplier comprises N readout electrodes (5), a cathode (1), an electron multiplier (2), N gating electrodes (3) and N anodes (4), wherein the cathode (1), the electron multiplier, the N gating electrodes and the N anodes (4) are arranged in a vacuum environment, and N is an integer greater than 1;

the cathode (1) and the electron multiplier (2) are arranged in parallel, a first gap is arranged between the cathode (1) and the electron multiplier, and the range of the first gap is 0.5-5 mm;

the N gating electrodes (3) are arranged in the first gap and used for applying gating pulses with different time parameters respectively to control whether electrons emitted by the cathode (1) can enter the electron multiplier (2), the total area of the N gating electrodes (3) is equal to the effective area of the cathode (1), a second gap is arranged between one side of each gating electrode (3) and the cathode (1), the range of the second gap is 0.2 mm-1 mm, a third gap is arranged between the other side of each gating electrode and the electron multiplier (2), and the range of the third gap is 0.3 mm-4 mm;

the N anodes (4) are arranged on one side, away from the cathode (1), of the electron multiplier (2) and used for collecting electrons multiplied by the electron multiplier (2), the N anodes (4) and the N gating electrodes (3) are arranged in a one-to-one correspondence mode, a fourth gap is arranged between the anodes (4) and the electron multiplier (2), and the range of the fourth gap is 1 mm-5 mm;

one end of each of the N readout electrodes (5) is connected with one side, away from the electron multiplier (2), of each of the N anodes (4), and the other end of each readout electrode is used for being connected with external equipment to output electrons collected by the anodes (4).

2. A high temporal resolution photomultiplier according to claim 1, wherein: the electron multiplier (2) is made of a secondary electron multiplication material.

3. A high time resolution photomultiplier according to claim 2, wherein: the electron multiplier (2) is a microchannel plate electron multiplier or a dozen electrode electron multiplier.

4. A high temporal resolution photomultiplier according to claim 3, wherein: the cathode (1) is an ultraviolet cathode, an infrared cathode or a visible light cathode;

the cathode (1) is of a thin plate structure, and the N gate electrodes (3) are distributed along the length direction of the cathode (1).

5. A high time resolution photomultiplier according to claim 4, wherein: the anode (4) is in a thin sheet shape or a conical shape;

the interior of the gating electrode (3) is of a regular hexagonal reticular structure, and the shape of the gating electrode (3) is the same as that of the anode (4).

6. A high time resolution photomultiplier according to claim 5, wherein: the readout electrode (5) is a cable with fixed impedance.

7. The high temporal resolution photomultiplier of claim 6, wherein: the reading electrode (5) is a metal wire or a coaxial cable.

8. A method for realizing high time resolution photomultiplier, based on any one of claims 1 to 7, comprising the steps of:

step 1, respectively applying fixed potentials with different sizes to a cathode (1), a gating electrode (3), an electron multiplier (2) and an anode (4);

a constant voltage difference V is formed between the gate electrode (3) and the cathode (1) _clo Preventing electrons emitted from the cathode (1) from passing through the gate electrode (3); a fixed electron acceleration voltage difference V is formed between the gate electrode (3) and the electron multiplier (2) _ac Allowing electrons passing through the gate electrode (3) to enter the electron multiplier (2); a fixed electron acceleration voltage difference V is formed between the electron multiplier (2) and the anode (4) _a So that the electrons multiplied by the electron multiplier (2) can enter the anode (4);

step 2, when optical signal detection is carried out, gating pulses with different time parameters are respectively applied to the N gating electrodes (3), wherein the gating pulses with different time parameters are as follows: t of pulse width of N gate pulses _d Same, T _d The value range of the N gating pulses is 1 ps-1 mu s, the rising edge starting time of the N gating pulses is sequentially delayed on a time axis, and the starting time difference of the rising edges of two adjacent gating pulses is delta t; or the starting time of the rising edge of the N gating pulses is the same, the pulse widths of the N gating pulses are sequentially increased, and the pulse width difference value of two adjacent gating pulses is delta t; the value range of delta t is 1 ps-500 ns;

the gating pulses applied by two adjacent gating electrodes (3) have overlapping time periods, the total time of the superposition of the gating pulses applied by N gating electrodes (3) is longer than the duration time of the optical signal to be detected, and the optical signal to be detected is not in a persistent state in the gating pulse duration period with the earliest rising edge starting time or the smallest pulse width;

the amplitude of the strobe pulse is V _g ，V _g ≥V _clo Enabling the N gate electrodes (3) to be in a gate state in a positive pulse time period of the corresponding gate pulse;

step 3, the anode (4) outputs a detection waveform signal in the time period when the corresponding gating electrode (3) is in the gating state and the optical signal to be detected is in the storage state;

sequencing the detected waveform signals according to the front-back sequence of the rising edges of the corresponding gating pulses of the N gating electrodes (3) on a time axis or the sequence of the pulse widths from short to long;

step 4, defining the first gated gate electrode (3) or the anode (4) corresponding to the gate electrode (3) with the shortest gating time as a basic anode (4), defining the characteristic charge quantity output in the non-overlapping time period of the detection waveform signals output by two adjacent anodes (4) as Q3, and calculating the characteristic charge quantity Q3 output in the non-overlapping time period of the rest anodes (4) except the basic anode (4), specifically:

integrating the detection waveform signal output by the anode (4) behind the two adjacent anodes (4) to obtain the total charge quantity Q1 output by the anode (4), and integrating the detection waveform signal output by the anode (4) behind the two adjacent anodes (4) to obtain the total charge quantity Q2 output by the anode (4), wherein Q3= Q1-Q2;

and step 5, respectively carrying out inverse integration processing on all the obtained characteristic charge quantities Q3 to obtain characteristic waveform signals corresponding to the anode (4), and carrying out fitting reconstruction on all the obtained characteristic waveform signals according to the time sequence information of the gating pulses with different time parameters to obtain detection waveforms with high time resolution.

9. The method of claim 8, wherein the photomultiplier comprises:

in step 1, V _clo ＜-5V，V _ac ＞10V，V _a ＞10V。

Images