Laser pulse detection circuit and laser energy detection method and system

Abstract

The invention provides a laser pulse detection circuit and a laser energy detection method and system, and the circuit comprises a photodiode which is used for converting an optical signal of a to-be-detected laser pulse into a pulse current signal; the conversion unit is used for converting the pulse current signal into a pulse voltage signal; the peak holding unit is used for holding the peak pulse voltage of the pulse voltage signal and outputting the peak pulse voltage; the analog-to-digital converter is used for collecting the peak pulse voltage and converting the peak pulse voltage into a digital signal; the pulse width detection unit is used for collecting the width of the pulse voltage signal so as to represent the pulse width of the laser pulse to be detected; and the release unit is used for releasing the peak pulse voltage held by the peak holding unit at the end of the current detection period. The peak value and the pulse width of the pulse voltage signal are detected at the same time, the peak value and the pulse width serve as virtual data for calculating the light energy of the laser, the linear relation with the actual waveform integral value is combined, and effective evaluation of the light energy is achieved.

Description

Technical Field

[0001] The present disclosure relates to the field of medical technologies, and particularly to a detection circuit for laser pulses, a laser energy detection method, and a system. Background Art

[0002] When lasers are applied to the medical field, precise energy control is required. The most important control method is the feedback detection means. Conventional energy control feedback is to convert the optical signal into an electrical signal based on the photoelectric effect of a photodiode, then amplify and transform the signal through a circuit, and finally convert it into a digital signal using an analog-to-digital converter as the basis for control. However, the existing detection methods can only detect the light intensity of the laser, cannot detect the pulse width, and also require a high-speed analog-to-digital converter and corresponding data processing capabilities, with relatively high requirements for devices and power consumption. Summary of the Invention

[0003] The purpose of the embodiments of the present disclosure is to provide a detection circuit for laser pulses, a laser energy detection method, and a system to solve the problems existing in the prior art.

[0004] The embodiments of the present disclosure adopt the following technical solutions: A detection circuit for laser pulses includes: a photodiode for converting the optical signal of the laser pulse to be measured into a pulsed current signal; a conversion unit for converting the pulsed current signal into a pulsed voltage signal; a peak holding unit for holding the peak pulsed voltage of the pulsed voltage signal and outputting the peak pulsed voltage; an analog-to-digital converter for collecting the peak pulsed voltage and converting the peak pulsed voltage into a digital signal; a pulse width detection unit for collecting the width of the pulsed voltage signal to characterize the pulse width of the laser pulse to be measured; and a release unit for releasing the peak pulsed voltage held by the peak holding unit at the end of the current detection period.

[0005] In some embodiments, the conversion unit at least includes: a first operational amplifier and a conversion resistor. The first input terminal of the first operational amplifier is connected to a reference voltage, the second input terminal of the first operational amplifier is connected to the negative electrode of the photodiode and one end of the conversion resistor, and the output terminal of the first operational amplifier is connected to the other end of the conversion resistor and serves as the output terminal of the conversion unit.

[0006] In some embodiments, the peak holding unit at least includes: a diode, a capacitor, and a second operational amplifier; wherein, the positive electrode of the diode is connected to the output terminal of the first operational amplifier, the negative electrode of the diode is connected to one side plate of the capacitor and the first input terminal of the second operational amplifier, the other side plate of the capacitor is grounded, and the output terminal of the second operational amplifier is connected to the second input terminal of the second operational amplifier and the input terminal of the analog-to-digital converter.

[0007] In some embodiments, the pulse width detection unit at least includes: a voltage dividing resistor, a comparator, a reference resistor, and a timer; wherein, one end of the voltage dividing resistor is connected to the output end of the first operational amplifier, the other end of the voltage dividing resistor is connected to the second input end of the comparator, one end of the reference resistor is connected to the first input end of the comparator, the other end of the reference resistor is grounded, the output end of the comparator is connected to the input end of the timer, and the timer starts timing when detecting the first transition edge of the pulse signal output by the comparator and ends timing when detecting the second transition edge of the pulse signal output by the comparator, so as to output the duration of the effective level of the pulse signal as the width of the pulse voltage signal.

[0008] In some embodiments, when detecting the first transition edge or after a preset duration from detecting the first transition edge, the timer sends a start instruction to the analog-to-digital converter to drive the analog-to-digital converter to perform analog-to-digital conversion.

[0009] In some embodiments, the release unit at least includes an N-type transistor, the drain of the N-type transistor is connected between one side plate of the capacitor and the first input end of the second operational amplifier, the source of the N-type transistor is grounded, the gate of the N-type transistor accesses a release signal, and when the release signal meets the conduction condition of the N-type transistor, the peak pulse voltage stored in the capacitor is released.

[0010] In some embodiments, when detecting the second transition edge, the timer outputs a release signal that meets the conduction condition to the gate of the N-type transistor.

[0011] The embodiments of the present disclosure also provide a laser energy detection method for a laser pulse detection circuit based on the above, at least including: receiving the digital signal output by the analog-to-digital converter and the width of the pulse voltage signal output by the pulse width detection unit; calculating the laser energy of the laser to be measured according to the preset calibration parameters, the digital signal, and the width.

[0012] In some embodiments, the preset calibration parameters are calibrated based on the following steps: using the detection circuit to detect a reference laser to obtain a reference digital signal output by the analog-to-digital converter and a reference width output by the pulse width detection unit, the reference laser having a fixed energy and a fixed frequency; calculating the optical energy of the reference laser based on the fixed energy and the fixed frequency with the optical power of the laser as the calibration basis; and fitting the preset calibration parameters by using linear regression according to the optical energy of the reference laser, the reference digital signal, and the reference width.

[0013] An embodiment of the present disclosure also provides a laser energy detection system for laser pulses, which at least includes: the detection circuit as described above; a control unit that executes the above-mentioned laser energy detection method.

[0014] The beneficial effects of the embodiments of the present disclosure are as follows: By using the detection circuit to simultaneously detect the peak value and pulse width of the pulse voltage signal as virtual data for calculating the optical energy of the laser, and combining its linear relationship with the actual waveform integral value, an effective evaluation of the optical energy can be achieved. Moreover, in the implementation process, there is no need to set a high-sampling analog-to-digital converter and a high-computing-power chip, effectively reducing the power consumption during the detection process; at the same time, by using the release unit to replace the discharge resistor, the detection frequency of the detection circuit is improved. Description of the Drawings

[0015] In order to more clearly illustrate the technical solutions in one or more embodiments of this specification or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the drawings described below are only some embodiments recorded in this specification. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0016] Figure 1 It is a schematic circuit diagram of a detection circuit for laser pulses provided by one or more embodiments of this specification;

[0017] Figure 2 It is a circuit schematic diagram of a detection circuit for laser pulses provided by one or more embodiments of this specification;

[0018] Figure 3 It is a flowchart of a laser energy detection method provided by one or more embodiments of this specification. Detailed Embodiments

[0019] In order to enable those skilled in the art of this technology to better understand the technical solutions in one or more embodiments of this specification, the following will clearly and completely describe the technical solutions in one or more embodiments of this specification in conjunction with the drawings in one or more embodiments of this specification. Obviously, the described embodiments are only some embodiments of this specification, rather than all embodiments. Based on one or more embodiments of this specification, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of this document.

[0020] The application of lasers in the medical field requires precise energy control. Among the control methods, the most important one is the feedback detection means. In the conventional energy control feedback, the photoelectric effect of a photodiode is used to convert the optical signal into an electrical signal, which is then amplified and transformed by a circuit. Finally, an analog-to-digital converter is used to convert it into a digital signal as the basis for control. However, the existing detection methods can only detect the light intensity of the laser and cannot detect the pulse width. At the same time, a high-speed analog-to-digital converter and corresponding data processing capabilities are required, which have relatively high requirements for device requirements and power consumption.

[0021] To solve the above problems, the first embodiment of the present disclosure provides a detection circuit for laser pulses. The circuit schematic diagram is as Figure 1 shown, and mainly includes the following functional parts: a photodiode 10 for converting the optical signal of the laser pulse to be measured into a pulse current signal; a conversion unit 20 for converting the pulse current signal into a pulse voltage signal; a peak holding unit 30 for holding the peak pulse voltage of the pulse voltage signal and outputting the peak pulse voltage; an analog-to-digital converter 40 for collecting the peak pulse voltage and converting the peak voltage into a digital signal; a pulse width detection unit 50 for collecting the width of the pulse voltage signal to characterize the pulse width of the laser pulse to be measured; and a release unit 60 for releasing the peak pulse voltage held by the peak holding unit 30 at the end of the current detection cycle.

[0022] Figure 2 shows the circuit schematic diagram of the detection circuit of this embodiment. The detection principle of the detection circuit of this embodiment will be described in detail below in combination with Figure 2 In this embodiment, the laser pulse to be measured irradiates on the photodiode 10. Based on the photoelectric effect, the photodiode 10 forms photocurrents with different magnitudes and durations according to the laser intensity and irradiation time (i.e., the pulse width of the laser). These photocurrents are used as pulse current signals for subsequent functional parts of the circuit to detect.

[0023] The conversion unit 20 is mainly used to convert the pulse current signal into a stable pulse voltage signal for convenient detection, and forms pulse voltage signals with different intensities and pulse widths according to the different magnitudes and durations of the pulse current signals. The conversion unit 20 mainly includes a first operational amplifier OPA1 and a conversion resistor R1. The first input terminal of the first operational amplifier OPA1 is connected to a reference voltage VR. The second input terminal of the first operational amplifier OPA1 is connected to the negative electrode of the photodiode 10 and one end of the conversion resistor R1. The output terminal of the first operational amplifier OPA1 is connected to the other end of the conversion resistor R1 and serves as the output terminal of the conversion unit 20. In addition, the first operational amplifier OPA1 is also powered by a supply voltage VCC.

[0024] The peak holding unit 30 of this embodiment includes at least a diode D1, a capacitor C, and a second operational amplifier OPA2. Among them, the positive electrode of the diode D1 is connected to the output terminal of the first operational amplifier OPA1, the negative electrode of the diode D1 is connected to one side plate of the capacitor C and the first input terminal of the second operational amplifier OPA2, the other side plate of the capacitor C is grounded, and the output terminal VOUT of the second operational amplifier OPA2 is connected to the second input terminal of the second operational amplifier OPA2 and the input terminal of the analog-to-digital converter 40. It should be noted that Figure 2 the specific circuit structure of the analog-to-digital converter 40 is not shown, and it can be directly implemented by using a conventional analog-to-digital converter. The specific model and type of this embodiment are not limited as long as the corresponding detection function is satisfied. During the actual detection process, the pulsed voltage signal charges the capacitor C and maintains the peak value of this voltage during the detection process. The second operational amplifier OPA2 is used to isolate the signal between the analog-to-digital converter and the previous stage to achieve stable signal output. The analog-to-digital converter 40 collects the signal output by the peak holding unit 30, continuously converts it into a digital signal to represent the voltage magnitude of the pulsed voltage signal, and uses the maximum value of the decimal data value V converted by the analog-to-digital converter during this detection period to represent the laser intensity to be detected.

[0025] The pulse width detection unit 50 characterizes the width of the laser pulse to be measured by collecting the width of the pulsed voltage signal. It mainly includes a voltage dividing resistor R2, a comparator Comp, a reference resistor R3, and a timer Timer. Among them, one end of the voltage dividing resistor R2 is connected to the output terminal of the first operational amplifier OPA1, the other end of the voltage dividing resistor R2 is connected to the second input terminal of the comparator Comp, one end of the reference resistor R3 is connected to the first input terminal of the comparator Comp, the other end of the reference resistor R3 is grounded, and the output terminal of the comparator Comp is connected to the input terminal of the timer Timer ( Figure 2 not shown). The timer Timer starts timing when detecting the first transition edge of the pulse signal TR output by the comparator Comp and ends timing when detecting the second transition edge of the pulse signal output by the comparator Comp, and uses the duration of the effective level of the pulse signal as the width of the pulsed voltage signal.

[0026] In actual implementation, the magnitude of the reference resistor R3 can be adjusted. Specifically, it can be adjusted according to different types of lasers and the models of other circuit components, etc., to achieve different detection accuracies. The pulsed voltage signal is divided by a voltage-dividing resistor and compared with the reference voltage formed across the reference resistor. The comparator Comp converts the level of its output high or low according to the comparison result. When the reference resistor is fixed, the duration of the pulsed voltage signal is characterized by the transition edge of the pulsed signal output by the comparator to serve as the duration of the laser pulse to be measured. Specifically, in this embodiment, the low level is used as the valid level of the pulsed signal. When the voltage value of the pulsed voltage signal is lower than the reference voltage, the comparator outputs an invalid high level. When the voltage value of the pulsed voltage signal is higher than the reference voltage, the comparator outputs a valid low level. During the actual detection process, when the timer detects the first transition edge when the output of the comparator changes from high level to low level within the current detection cycle, it starts timing, indicating that the laser is irradiating the photodiode at this time. When the timer detects the second transition edge within the current detection cycle, it means that the comparator outputs an invalid level again, that is, the laser stops irradiating and no pulsed voltage signal is generated in the circuit. At this time, the timer stops timing. Finally, the duration recorded by the timer is the duration of the laser irradiation within this detection cycle, that is, the duration W of the laser irradiation.

[0027] In some embodiments, the analog-to-digital converter can be controlled according to the transition edge situation detected by the timer. For example, when the timer detects the first transition edge, a start instruction is sent to the analog-to-digital converter to make it perform analog-to-digital conversion, or after a preset duration after the timer detects the first transition edge, a start instruction is sent to the analog-to-digital converter to make it work, so as to avoid the pulsed voltage signal not being in the rising period when the analog-to-digital converter performs conversion, resulting in an increase in the power consumption of the analog-to-digital converter. During the actual implementation process, the analog-to-digital converter can be in a low-power mode before receiving the start instruction to further reduce the power consumption. In addition, the timer can also send a low-power instruction to the analog-to-digital converter when it detects the second transition edge to make it stop analog-to-digital conversion and re-enter the low-power mode until the first transition edge of the next detection cycle arrives.

[0028] After the current laser to be measured is detected, the peak pulse voltage stored in the capacitor C in the peak holding unit 30 can be released through the release unit 60 to meet the detection needs of the next laser to be measured. As Figure 2As shown, the release unit 60 includes at least an N-type transistor Q1. Wherein, the drain of the N-type transistor Q1 is connected between one side plate of the capacitor C and the first input terminal of the second operational amplifier OP2. The source of the N-type transistor Q1 is grounded, and the gate of the N-type transistor Q1 receives the release signal S. When the release signal meets the conduction condition of the N-type transistor Q1, the peak pulse voltage stored in the capacitor C is released. In some embodiments, the release signal can be a PWM signal. The high level in the PWM signal triggers Q1 to conduct, realizing the discharge of the capacitor C. When the PWM signal is at a low level, Q1 is turned off, and the capacitor C realizes charging or peak voltage holding. The condition for triggering the PWM signal to switch to the effective level that meets the conduction condition of the N-type transistor Q1 can be that the timer detects the second transition edge, that is, when it is determined that the current laser to be measured stops. At this time, the timer can output a release signal that meets the conduction condition to the gate of the N-type transistor Q1, realizing the release of the peak voltage.

[0029] When the release unit 60 releases the peak voltage of the capacitor, the N-type transistor Q1 can be turned off according to the preset discharge duration, that is, the duration of the effective level of the release signal is fixed. When the preset discharge duration arrives, the release signal switches to the invalid level, and the N-type transistor Q1 is turned off, so that the capacitor C meets the conditions of charging or peak holding during the next detection; it should be noted that the preset discharge duration can be set according to the parameters of relevant devices in the circuit. For example, it is calculated in combination with the maximum capacitance value of the capacitor and the aspect ratio of the transistor channel width and length, and appropriately extended based on the calculation result to ensure the integrity of the discharge result of the capacitor C. In some embodiments, the release unit 60 can also be controlled according to the real-time conversion result of the analog-to-digital converter. For example, during the discharge process, the analog-to-digital converter converts the current remaining charge situation in the capacitor in real time. As the capacitor discharges continuously, the input and output of the analog-to-digital converter also change continuously. When the charge stored in the capacitor is released to a certain extent, the conversion result of the analog-to-digital converter will also drop below a specific value. Therefore, when the output result of the analog-to-digital converter drops to a specific value, it is determined that the capacitor discharge is completed, and the transistor can be turned off.

[0030] During one detection process, the intensity of the laser pulse can be detected through the peak holding unit and the analog-to-digital converter, and the pulse width can be output through the pulse width detection unit. Finally, combining the digital signal representing the intensity of the pulse voltage signal output by the analog-to-digital converter and the width of the pulse voltage signal output by the pulse width detection unit, the laser energy of the laser to be measured is calculated based on the preset calibration parameters, and combined with the energy requirement of the actual laser, the laser to be measured is adjusted to meet the medical use.

[0031] In this embodiment, the detection circuit simultaneously detects the peak value and pulse width of the pulsed voltage signal as virtual data for calculating the optical energy of the laser. Combining its linear relationship with the actual waveform integral value, the effective evaluation of the optical energy is realized. Moreover, during the implementation process, there is no need to set a high-sampling analog-to-digital converter and a high-computing-power chip, effectively reducing the power consumption during the detection process. At the same time, the release unit is used to replace the discharge resistor, improving the detection frequency of the detection circuit.

[0032] The second embodiment of the present disclosure provides a method for detecting laser energy. This method can be implemented based on any electronic device with an operation function. At the same time, this electronic device can communicate with the detection circuit provided in the first embodiment of the present disclosure or control the detection circuit, and can perform real-time adjustment of the laser in combination with the detection results. Figure 3 The flowchart of the method for detecting laser energy in this embodiment is shown, mainly including steps S10 and S20, where:

[0033] S10, receiving the digital signal output by the analog-to-digital converter and the width of the pulsed voltage signal output by the pulse width detection unit;

[0034] S20, calculating the laser energy of the laser to be measured according to the preset calibration parameters, digital signal, and width.

[0035] At the beginning of the detection, the analog-to-digital converter is in the low-power mode. When the laser to be measured irradiates the photodiode, the detection circuit starts to work. As the pulsed voltage signal increases, the pulsed voltage signal received by the comparator is higher than the reference voltage, and its output switches from the invalid level to the valid level. When the timer detects the first transition edge, it starts timing and triggers the analog-to-digital converter to start analog-to-digital conversion. At the same time, the capacitor charges as the pulsed voltage signal increases and maintains the peak pulsed voltage value. After receiving the start instruction, the analog-to-digital converter continuously converts the pulsed voltage signal, and the electronic device continuously receives the digital signal output by the analog-to-digital converter, taking the maximum value of the converted decimal digital value V as the intensity of the laser in this detection. As the laser pulse stops, the pulsed voltage signal weakens continuously, and the output of the comparator switches from the valid level to the invalid level. The timer determines that the laser pulse stops and ends the timing according to the second transition edge, taking the time length between the start of timing and the end of timing as the width W of the pulsed voltage signal, that is, the duration of the laser pulse, and transmits it to the electronic device. Finally, the electronic device calculates the laser energy E of the laser to be measured by means of linear fitting based on the received width value W, digital value V, and the preset calibration parameters obtained by pre-calibration.

[0036] In this embodiment, the preset calibration parameters are mainly calibrated based on the following steps. First, the detection circuit of the first embodiment of the present disclosure is used to detect a reference laser, which has a known fixed energy and a fixed frequency. Through the detection circuit, the reference digital signal output by the analog-to-digital converter and the reference width output by the pulse width detection unit can be obtained. Subsequently, according to the known fixed energy and fixed frequency of the reference laser, with the optical power of the reference laser as the calibration basis, the optical energy of the reference laser is calculated. Finally, using linear regression modeling, based on the optical energy, reference digital signal, and reference width of the reference laser, with the optical energy as the dependent variable and the reference digital signal and reference width as the independent variables, the preset calibration parameters B0 and B1 are fitted. When calculating the optical energy of the laser to be measured finally, it can be realized according to the following formula:

[0037] E = B0 + B1 * V * W.

[0038] It should be noted that when actually setting the reference laser, the optical energy of the reference laser can be set by setting different combinations of pulse widths and intensities, and linear regression fitting is performed through multiple groups of combinations of optical energy, reference digital signals, and reference widths. During the fitting process, the independent variables can also increase the power functions of the reference digital signal and the reference width to obtain non-linear compensation and transform it into a multiple linear regression to increase the accuracy of the calibration parameters. At this time, the number of preset calibration parameters may increase, and the corresponding function of calculating the optical energy will also change accordingly. Specifically, it can be adjusted according to the actual accuracy requirements and calculation power consumption, etc. This embodiment will not be specifically described.

[0039] This embodiment uses the product of the energy peak and the pulse width as virtual data, and uses its linear relationship with the integral value (optical energy) of the actual waveform to quickly and effectively estimate the optical energy. The overall detection process does not require high-speed sampling, has a small calculation amount and a low sampling rate, and does not require continuous sampling and calculation when there is no pulse, effectively reducing the power consumption while meeting the optical energy output, and reducing the cost of the equipment required for the overall detection.

[0040] The third embodiment of the present disclosure provides a laser energy detection system for laser pulses. The laser energy detection system at least includes the detection circuit provided in the first embodiment of the present disclosure and a control unit that can execute the detection method provided in the second embodiment of the present disclosure. Through the cooperation of the two, the optical energy of the laser pulse is detected, making the overall system architecture simple and easy to build, and it does not require a high-speed chip or high-sampling-rate equipment to achieve, effectively reducing the system power consumption and operating cost while meeting the optical energy calculation.

[0041] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present disclosure, rather than to limit them; although the present disclosure has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements for some or all of the technical features; and these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present disclosure.

Claims

1. A laser pulse detection circuit, characterized in that: include: A photodiode, used for converting the optical signal of the laser pulse to be measured into a pulse current signal; A conversion unit, used for converting the pulse current signal into a pulse voltage signal; A peak holding unit, used for holding a peak pulse voltage of the pulse voltage signal and outputting the peak pulse voltage; an analog-to-digital converter, used for collecting the peak pulse voltage and converting the peak pulse voltage into a digital signal; A pulse width detection unit, used for collecting the width of the pulse voltage signal to characterize the pulse width of the laser pulse to be measured; The release unit is used to release the peak pulse voltage held by the peak holding unit at the end of the current detection cycle.

2. The detection circuit according to claim 1, characterized in that: The conversion unit at least comprises: A first operational amplifier and a conversion resistor, wherein the first input terminal of the first operational amplifier is connected to a reference voltage, the second input terminal of the first operational amplifier is connected to the cathode of the photodiode and one end of the conversion resistor, and the output terminal of the first operational amplifier is connected to the other end of the conversion resistor and serves as the output terminal of the conversion unit.

3. The detection circuit according to claim 2, characterized in that: The peak holding unit at least includes: a diode, a capacitor and a second operational amplifier; wherein the anode of the diode is connected to the output end of the first operational amplifier, the cathode of the diode is connected to one side plate of the capacitor and the first input end of the second operational amplifier, the other side plate of the capacitor is grounded, and the output end of the second operational amplifier is connected to the second input end of the second operational amplifier and the input end of the analog-to-digital converter.

4. The detection circuit according to claim 3, characterized in that: The pulse width detection unit at least includes: a voltage-dividing resistor, a comparator, a reference resistor and a timer; wherein, one end of the voltage-dividing resistor is connected to the output end of the first operational amplifier, the other end of the voltage-dividing resistor is connected to the second input end of the comparator, one end of the reference resistor is connected to the first input end of the comparator, the other end of the reference resistor is grounded, the output end of the comparator is connected to the input end of the timer, the timer starts timing when the first transition edge of the pulse signal output by the comparator is detected, and ends timing when the second transition edge of the pulse signal output by the comparator is detected, so as to output the effective level duration of the pulse signal as the width of the pulse voltage signal.

5. The detection circuit according to claim 4, characterized in that: When the timer detects the first conversion edge or after a preset time period of detecting the first conversion edge, the timer sends a start instruction to the analog-to-digital converter to drive the analog-to-digital converter to perform analog-to-digital conversion.

6. The detection circuit according to claim 4, characterized in that: The release unit at least includes an N-type transistor, the drain of the N-type transistor is connected between a side plate of the capacitor and the first input terminal of the second operational amplifier, the source of the N-type transistor is grounded, the gate of the N-type transistor is connected to a release signal, and when the release signal meets the conduction condition of the N-type transistor, the peak pulse voltage stored in the capacitor is released.

7. The detection circuit according to claim 6, characterized in that: When the timer detects the second conversion edge, it outputs a release signal satisfying the conduction condition to the gate of the N-type transistor.

8. A laser energy detection method based on the laser pulse detection circuit according to any one of claims 1 to 7, characterized in that: At least: Receiving the digital signal output by the analog-to-digital converter and the width of the pulse voltage signal output by the pulse width detection unit; The laser energy of the laser to be measured is calculated according to the preset calibration parameters, the digital signal and the width.

9. The laser energy detection method according to claim 8, characterized in that: The preset calibration parameters are calibrated based on the following steps: Using a detection circuit to detect a reference laser, obtaining a reference digital signal output by the analog-to-digital converter and a reference width output by a pulse width detection unit, wherein the reference laser has a fixed energy and a fixed frequency; According to the fixed energy and the fixed frequency, the optical energy of the reference laser is calculated using the optical power of the laser as a calibration basis; The preset calibration parameters are obtained by fitting using a linear regression method according to the light energy of the reference laser, the reference digital signal and the reference width.

10. A laser energy detection system for laser pulses, characterized in that: At least: The detection circuit as claimed in any one of claims 1 to 7; A control unit, wherein the control unit executes the laser energy detection method according to claim 8 or 9.

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