Optimal bias value setting method based on four-quadrant APD detector

Abstract

The invention belongs to the field of photoelectric detection, and particularly relates to a method for setting an optimal bias value based on a four-quadrant APD detector, which comprises the following steps of: calibrating ideal bias values of the four-quadrant APD detector at different environment temperatures; fitting an optimal bias voltage value and temperature value curve of the four-quadrant APD detector according to the calibrated temperature value and the ideal bias voltage value; carrying out self-checking on the optimal bias value and temperature value curve; and determining the bias voltage value when the noiseless signal reaches the interception trigger threshold value under the current environment temperature value as the optimal bias voltage value set by the four-quadrant detector. According to the invention, the four-quadrant APD detector can be ensured to have the optimal detection capability when working, and the problems that the optimal bias value cannot be determined because the four-quadrant APD detector is influenced by ambient temperature and background light interference, and the optimal bias value is inconsistent because different bias power supplies and different four-quadrant APD detectors are inconsistent are solved.

Description

Technical Field

[0001] The present invention belongs to the field of optoelectronic detection, and specifically relates to a method for setting the optimal bias voltage value of a four-quadrant APD detector, especially a method that can meet the setting of the optimal bias voltage value by designing relevant program steps. Background Art

[0002] Four-quadrant APD detectors are increasingly widely used in the field of optoelectronic detection. The setting of the bias voltage value of a four-quadrant APD detector determines the detection ability of the detector. Due to environmental temperature, background light interference, the consistency of the output voltage values of different bias power supplies, and the consistency between different four-quadrant APD detectors, the optimal bias voltage value of the four-quadrant detector is not a fixed value. Under specific temperature and background light interference, if the bias voltage value is set too high, the signal-to-noise ratio will decrease, easily leading to false signal triggering and generating false alarm signals, which affects the true measurement effect; if the bias voltage value is set too low, the detection sensitive range of the detector will be reduced and the detection ability will decline. The setting of the optimal bias voltage value of the four-quadrant detector is a prerequisite for ensuring the best detection ability of the four-quadrant detector. Summary of the Invention

[0003] The purpose of the present invention is to set the optimal bias voltage value of a four-quadrant APD detector, ensure the best working state of the four-quadrant APD detector, eliminate the negative effects caused by factors such as the environment and the consistency between devices, and make the four-quadrant APD detector obtain the best application in actual use.

[0004] The technical solution adopted by the present invention to achieve the above purpose is:

[0005] A method for setting the optimal bias voltage value of a four-quadrant APD detector, comprising the following steps:

[0006] 1) Calibrate the ideal bias voltage value of the four-quadrant APD detector at different environmental temperatures;

[0007] 2) According to the calibrated temperature value and the ideal bias voltage value, fit the curve of the optimal bias voltage value and the temperature value of the four-quadrant APD detector;

[0008] 3) Self-check the curve of the optimal bias voltage value and the temperature value;

[0009] 4) Determine the bias voltage value at which the noise-free signal reaches the capture trigger threshold at the current environmental temperature value, and use it as the optimal bias voltage value set for the four-quadrant detector.

[0010] The specific content of step 1) is:

[0011] Place the four - quadrant APD detector in a high - and - low - temperature chamber. At different ambient temperature values, adjust the bias voltage value so that at a specific temperature value, the detector noise floor just does not reach the set capture trigger threshold. Record the current bias voltage value as the ideal bias voltage value.

[0012] The capture trigger threshold is the signal sampling trigger voltage threshold set in the controller after the analog signal output by the four - quadrant APD detector is amplified, held, and extended and sent to the controller.

[0013] The specific content of step 4) is as follows:

[0014] Power on the four - quadrant APD detector, collect the current ambient temperature value, determine the preset bias voltage value according to the optimal bias voltage value - temperature value curve. If there is a noise signal reaching the capture trigger threshold, gradually reduce the bias voltage value point by point until there is no noise trigger; if there is no noise signal reaching the capture trigger threshold, gradually increase the bias voltage value point by point until there is a noise signal reaching the capture trigger threshold, and then gradually reduce the bias voltage value point by point until there is no noise signal reaching the capture trigger threshold, and correct the optimal bias voltage value - temperature value curve.

[0015] A system for setting the optimal bias voltage value of a four - quadrant APD detector includes:

[0016] A bias voltage value calibration module for calibrating the ideal bias voltage value of the four - quadrant APD detector at different ambient temperatures;

[0017] A curve fitting module for fitting the optimal bias voltage value - temperature value curve of the four - quadrant APD detector according to the calibrated temperature value and ideal bias voltage value;

[0018] A self - calibration module for self - calibrating the optimal bias voltage value - temperature value curve;

[0019] An optimal bias voltage value determination module for determining the bias voltage value at which there is no noise signal reaching the capture trigger threshold at the current ambient temperature value as the optimal bias voltage value set for the four - quadrant detector.

[0020] An apparatus for setting the optimal bias voltage value of a four - quadrant APD detector includes a memory and a processor; the memory is used to store a computer program; the processor is used to implement the method for setting the optimal bias voltage value of a four - quadrant APD detector when executing the computer program.

[0021] A computer - readable storage medium stores a computer program, and when the computer program is executed by a processor, it implements the method for setting the optimal bias voltage value of a four - quadrant APD detector.

[0022] The present invention has the following beneficial effects and advantages:

[0023] The present invention can ensure that the four - quadrant APD detector has the best detection ability during operation, eliminate the problem that due to the influence of environmental temperature and background light interference on the four - quadrant APD detector, the optimal bias voltage value cannot be determined, and eliminate the inconsistency of the optimal bias voltage value caused by the inconsistency between different bias power supplies and different four - quadrant APD detectors. Brief Description of the Drawings

[0024] Figure 1 Schematic diagram of related components of a method for setting the optimal bias voltage value of a four - quadrant APD detector;

[0025] Figure 2 Flowchart of a method for setting the optimal bias voltage value of a four - quadrant APD detector. Detailed Embodiment

[0026] The present invention will be further described in detail below with reference to the drawings and embodiments.

[0027] The present invention includes the following steps:

[0028] 1) Place the four - quadrant APD detector in a high - low temperature chamber. At different environmental temperature values, adjust the bias voltage value to determine that when the detector bottom noise just does not reach the set capture trigger threshold at a specific temperature value, record the current bias voltage value, and thus calibrate the ideal bias voltage value of the four - quadrant APD detector at different environmental temperatures;

[0029] 2) According to the calibrated temperature values and ideal bias voltage value points, fit the curve of the optimal bias voltage value and temperature value of the four - quadrant APD detector, so that the calibrated values can be approximately applicable to the entire range of the calibrated temperature;

[0030] 3) Power on the four - quadrant APD detector, collect the current environmental temperature value, and determine the preset bias voltage value according to the calibrated bias voltage - temperature value curve. If there is a noise signal reaching the capture trigger threshold, gradually reduce the bias voltage value point by point until there is no noise trigger; if there is no noise signal reaching the capture trigger threshold, gradually increase the bias voltage value point by point until there is a noise signal reaching the capture trigger threshold, and then gradually reduce the bias voltage value point by point until there is no noise signal reaching the capture trigger threshold. Perform power - on self - calibration in this way to eliminate the differences introduced by curve fitting, different intensities of background light interference, and inconsistencies between different detectors.

[0031] 4) After self - inspection, determine the bias voltage value at which there is no noise signal reaching the capture trigger threshold at the current environmental temperature value, and use this as the optimal bias voltage value set for the four - quadrant detector.

[0032] The different environmental temperature values are the sub - divided temperature values within the nominal operating temperature range of the four - quadrant APD detector, that is, the interval temperature values after dividing the operating temperature range into several partitions;

[0033] The interception trigger threshold is the signal sampling trigger voltage threshold set in the controller after the analog signal output by the four-quadrant APD detector is amplified, held and extended, and the signal is the signal collected by the analog-to-digital converter from the output of the peak-holding circuit.

[0034] The current ambient temperature value is the ambient temperature value collected after the four-quadrant APD detector is powered on under the actual application environmental conditions of the detector.

[0035] Embodiment

[0036] See Figure 1 , the main components related to a method for setting the optimal bias voltage value based on a four-quadrant detector mainly include: 1 four-quadrant APD detector, 2 thermistor, 3 voltage follower, 4 preamplifier, 5 automatic gain circuit, 6 peak-holding circuit, 7 controller, 8 negative high-voltage power supply

[0037] See Figure 2 , a method flow for setting the optimal bias voltage value based on a four-quadrant detector. First, set the voltage threshold to determine the maximum amplitude of the background noise. When the maximum amplitude of the background noise is less than this threshold, it is considered that the bias voltage value is reasonable or small, and there is no noise mis-triggering problem. When it is greater than this threshold, it is considered that the bias voltage value is large at this time and there is a noise mis-triggering problem

[0038] Secondly, place the four-quadrant APD detector in a high and low temperature chamber. Divide the temperature range into 20 equal parts according to the nominal operating temperature range of the four-quadrant APD detector. At different divided ambient temperature values, adjust the bias voltage value to ensure that there is no noise triggering phenomenon in the signal collected by the controller from the peak-holding circuit at the divided temperature values, and record the current bias voltage value, so as to calibrate the ideal bias voltage value of the four-quadrant APD detector at different ambient temperatures;

[0039] Thirdly, according to the calibrated temperature value and the ideal bias voltage value points, fit the curve of the optimal bias voltage value and the temperature value of the four-quadrant APD detector, so that the calibrated value can be approximately applicable to the entire range of the calibrated temperature;

[0040] Thirdly, power on the four-quadrant APD detector, collect the current ambient temperature value, and determine the preset bias voltage value according to the bias voltage-temperature value curve fitted by the calibrated value. If there is noise triggering, gradually reduce the bias voltage value until there is no noise triggering; if there is no noise mis-triggering, gradually increase the bias voltage value until there is noise, and then gradually reduce the bias voltage value until there is no noise triggering. Perform power-on self-checking in this way to eliminate the differences introduced by curve fitting, different strong and weak background light interferences, and inconsistencies between different detectors.

[0041] Finally, after self-checking, the bias voltage value that is not erroneously triggered at the current ambient temperature value is determined, and this bias voltage value is used as the optimal bias voltage value set for the quadrant detector for output.

Claims

1. A method for setting the optimal bias voltage value of a four - quadrant APD detector, characterized in that, Including the following steps: 1) Calibrate the ideal bias voltage value of the quadrant APD detector at different ambient temperatures; 2) Fit the curve of the optimal bias voltage value and the temperature value of the quadrant APD detector according to the calibrated temperature value and the ideal bias voltage value; 3) Perform self-check on the curve of the optimal bias voltage value and the temperature value; 4) Determine the bias voltage value at which the noise-free signal reaches the capture trigger threshold at the current ambient temperature value, and use it as the optimal bias voltage value set for the quadrant detector.

2. The method for setting the optimal bias voltage value of a four - quadrant APD detector according to claim 1, characterized in that, The specific content of step 1) is as follows: Place the quadrant APD detector in a high and low temperature chamber. At different ambient temperature values, adjust the bias voltage value so that the detector background noise of the quadrant APD detector just does not reach the set capture trigger threshold at a specific temperature value, and record the current bias voltage value as the ideal bias voltage value.

3. The method for setting the optimal bias voltage value of a four - quadrant APD detector according to claim 2, characterized in that, The capture trigger threshold is the signal sampling trigger voltage threshold set in the controller after the analog signal output by the quadrant APD detector is amplified, held and extended and sent to the controller.

4. The method for setting the optimal bias voltage value of a four - quadrant APD detector according to claim 1, characterized in that, The specific content of step 4) is as follows: Power on the quadrant APD detector, collect the current ambient temperature value, and determine the preset bias voltage value according to the curve of the optimal bias voltage value and the temperature value. If there is a noise signal reaching the capture trigger threshold, gradually reduce the bias voltage value until there is no noise trigger; if there is no noise signal reaching the capture trigger threshold, gradually increase the bias voltage value until there is a noise signal reaching the capture trigger threshold, and then gradually reduce the bias voltage value until there is no noise signal reaching the capture trigger threshold, and correct the curve of the optimal bias voltage value and the temperature value.

5. A system for setting the optimal bias voltage value of a four - quadrant APD detector, characterized in that, Including: A bias voltage value calibration module for calibrating the ideal bias voltage value of the quadrant APD detector at different ambient temperatures; A curve fitting module for fitting the curve of the optimal bias voltage value and the temperature value of the quadrant APD detector according to the calibrated temperature value and the ideal bias voltage value; A self-check module for performing self-check on the curve of the optimal bias voltage value and the temperature value; An optimal bias voltage value determination module for determining the bias voltage value at which the noise-free signal reaches the capture trigger threshold at the current ambient temperature value, and using it as the optimal bias voltage value set for the quadrant detector.

6. A device for setting the optimal bias voltage value of a four - quadrant APD detector, characterized in that, Including a memory and a processor; the memory is used to store a computer program; the processor is used to implement a method for setting the optimal bias voltage value of a quadrant APD detector as described in any one of claims 1-4 when executing the computer program.

7. A computer - readable storage medium, characterized in that, A computer program is stored on the storage medium, and when the computer program is executed by the processor, a method for setting the optimal bias voltage value of a quadrant APD detector as described in any one of claims 1-4 is implemented.

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