A photoelectric detector output signal large range detection circuit and detection method thereof

Abstract

The present invention relates to a photodetector D1, and specifically to a large-range detection circuit for a photodetector output signal and a detection method thereof, which solves the technical problem that a large-range output signal generated when a large-intensity range laser irradiates the photodetector D1 is difficult to detect with high precision over the full range. A large-range detection circuit for a photodetector output signal comprises an amplifier A1, an amplifier A2, a voltage acquisition device ADC1, a voltage acquisition device ADC2, and a photodetector D1, a sampling resistor R1 and a sampling resistor R2 connected in series; the photodetector D1 is arranged on the light output path of the laser; the two input ends of the amplifier A1 are respectively connected to the two ends of the sampling resistor R1, and the output end thereof is connected to the input end of the voltage acquisition device ADC1; the two input ends of the amplifier A2 are respectively connected to the two ends of the sampling resistor R2, and the output end thereof is connected to the input end of the voltage acquisition device ADC2. The present invention can realize accurate detection of input optical signals with intensities of 5 to 6 orders of magnitude.

Description

Technical Field

[0001] The present invention relates to a photoelectric detector D1, and in particular to a large-range detection circuit and a detection method of a photoelectric detector output signal. Background Art

[0002] Photodetectors convert light radiation energy into current signals for measurement and are the most commonly used optical signal measuring devices. In the field of laser performance parameter detection, with the improvement of laser technology, the laser power density continues to increase. The laser power density at the photodetector position usually covers 3 to 4 orders of magnitude, and sometimes even 5 orders of magnitude, which puts higher requirements on the detection capability of the measurement system. For the measurement system, the current typical photodetector has relatively small noise such as dark current, and its response dynamic range can reach 5 to 6 orders of magnitude, which can meet the above laser power detection requirements. However, the output current of the photodetector has noise after the current-voltage conversion amplification. Under normal circumstances, the peak-to-peak value of the noise is below 5 millivolts, and the maximum voltage that the voltage acquisition device can collect is 10V. At this time, its dynamic range is less than 4 orders of magnitude, which is difficult to meet the above detection requirements.

[0003] In order to solve the above problems, logarithmic amplifiers are traditionally used. To achieve signal acquisition with a larger dynamic range, more dual-gain circuit units consisting of high-gain limiting amplifiers and gain amplifiers are usually required in cascade. This amplifier structure has high power consumption, usually more than 1.5W, and AC coupling is used between amplifiers at each level. The integration level is low and the modular volume is large. The AD8309 integrated chip (CN101938255) of ADI Company achieves high dynamic range logarithmic amplification in a smaller volume, but has the disadvantages of fixed slope and ending. In addition, the logarithmic amplifier itself has problems such as reducing the signal-to-noise ratio of large signals and logarithmic consistency errors. Summary of the invention

[0004] The purpose of the present invention is to solve the technical problem that the large-range output signal generated when a large-intensity range laser irradiates a photoelectric detector is difficult to detect with high precision over the entire range, and to provide a large-range detection circuit for the output signal of a photoelectric detector and a detection method thereof, so as to achieve accurate detection of input light signals with intensities of 5 to 6 orders of magnitude, and the circuit is simple and reliable, while taking into account the requirements of easy implementation of the circuit and high efficiency and cost-effectiveness.

[0005] In order to solve the above technical problems, the technical solution adopted by the present invention is:

[0006] A large-range detection circuit for output signals of a photoelectric detector, which is special in that it includes an amplifier A1, an amplifier A2, a voltage acquisition device ADC1, a voltage acquisition device ADC2, and a photoelectric detector D1, a sampling resistor R1 and a sampling resistor R2 connected in series in sequence;

[0007] The photodetector D1 is arranged on the output light path of the laser; the cathode of the photodetector D1 is used to be connected to the external voltage V1, and the anode of the photodetector D1 is connected to the sampling resistor R1;

[0008] The two input terminals of the amplifier A1 are respectively connected to the two ends of the sampling resistor R1, and the output terminal thereof is connected to the input terminal of the voltage acquisition device ADC1;

[0009] The two input terminals of the amplifier A2 are respectively connected to the two ends of the sampling resistor R2, and the output terminal thereof is connected to the input terminal of the voltage acquisition device ADC2;

[0010] The other end of the sampling resistor R2 is grounded.

[0011] Furthermore, the photodetector D1 is a photovoltaic InGaAs detector.

[0012] Furthermore, the amplifier A1 and the amplifier A2 are instrumentation amplifiers.

[0013] Furthermore, the peak-to-peak value of the output noise of the amplifier A1 is not greater than 5mV, and the maximum output voltage is not less than 10V;

[0014] The peak-to-peak value of the output noise of amplifier A2 is no more than 5mV, and the maximum output voltage is no less than 10V.

[0015] Furthermore, the voltage acquisition device ADC1 and the voltage acquisition device ADC2 are both oscilloscopes or data acquisition devices.

[0016] Furthermore, the voltage collection range of the voltage collection device ADC1 and the voltage collection device ADC2 is not less than 0-10V.

[0017] Furthermore, the accuracy of the sampling resistor R1 and the sampling resistor R2 are both 1‰.

[0018] At the same time, the present invention also provides a method for detecting a large range of a photoelectric detector output signal, which is special in that it includes the following steps:

[0019] S1, setting circuit parameters, the circuit parameters include external voltage V1, sampling resistor R1, sampling resistor R2, amplification factor G1 of amplifier A1, and amplification factor G2 of amplifier A2;

[0020] S2, connecting the voltage acquisition device ADC1 and the voltage acquisition device ADC2;

[0021] S3, applying an external voltage to the photodetector D1;

[0022] S4, recording the voltage Vb1 collected by the voltage collection device ADC1 and the voltage Vb2 collected by the voltage collection device ADC2;

[0023] S5, using laser to irradiate the photodetector D1, and recording the voltage Vo1 collected by the voltage collection device ADC1 and the voltage Vo2 collected by the voltage collection device ADC2;

[0024] S6. Calculate the photocurrent Id output by the photodetector D1 when it is irradiated by laser.

[0025] Furthermore, S1 is specifically:

[0026] S1.1) Determine the minimum current Imin and the maximum current Imax output by the photodetector D1 according to application requirements;

[0027] S1.2) determining an external voltage V1 according to the reverse bias voltage that the photodetector D1 can withstand;

[0028] S1.3) Estimate the resistance value of the sampling resistor R1, the estimation method is R1 = (V1-1) / Imax;

[0029] S1.4) determining the sampling resistor R1 according to the resistance estimation result of the sampling resistor R1 and the resistance accuracy requirement;

[0030] S1.5) Calculate the resistance of the sampling resistor R2, the calculation method is R2 = R1 / A;

[0031] S1.6) Calculate the gain G1 of amplifier A1, the calculation method is G1 = Vmin / (R1*Imin), where Vmin is twice the peak-to-peak value of the output voltage noise of amplifier A1;

[0032] Calculate the amplification factor G2 of the amplifier A2, the calculation method is G2 = Vmax / (R2*Imax), where Vmax is the maximum voltage that can be collected by the voltage collection device ADC2;

[0033] Furthermore, R1 / R2=Vmin / Vmax.

[0034] Furthermore, the value of A is 1000; the value of Vmin is 10mV; and the value of Vmax is 10V.

[0035] Furthermore, S6 is specifically:

[0036] S6.1) Calculate the output signal voltage Vs1 of the voltage acquisition device ADC1, the calculation method is Vs1 = Vo1 - Vb1;

[0037] S6.2) Calculate the output signal voltage Vs2 of the voltage acquisition device ADC2, the calculation method is Vs2 = Vo2 - Vb2;

[0038] S6.3) Determine and determine the output voltage Vs of the detection circuit

[0039] If Vs2≤10mV, then Vs=Vs1;

[0040] If Vs1>10V, then Vs=Vs2;

[0041] S6.4) Calculate the photocurrent Id output by the photodetector D1 when it is irradiated by laser

[0042] If Vs=Vs1, then Id=Vs / (G1*R1);

[0043] If Vs=Vs2, then Id=Vs / (G2*R2).

[0044] Compared with the prior art, the technical solution of the present invention has the following beneficial effects:

[0045] 1. The photoelectric detector output signal large-range detection circuit of the present invention connects the two-stage sampling resistor R1 and the sampling resistor R2 in series to the photoelectric detector D1, sets the sampling ratio according to the dynamic range of the detection circuit, amplifies and collects the sampling voltage at the same time, and selects it according to the collected voltage value. Based on the idea of ​​converting the number of channels into range, it can realize accurate detection of input optical signals with intensities of 5 to 6 orders of magnitude.

[0046] 2. The present invention realizes accurate detection of the large dynamic range signal output by the photodetector D1. The detection circuit adopts sampling resistors for sampling. The resistor sampling ratio can be adjusted according to the measurement dynamic range requirements, and has wide applicability.

[0047] 3. The sampling ratios of the sampling resistors R1 and R2 of the present invention match the dynamic ranges of the voltage acquisition devices ADC1 and ADC2, that is, the sampling ratios of the sampling resistors must be less than or equal to the measurement dynamic ranges of the voltage acquisition devices. In particular, when the sampling ratios of the sampling resistors are equal to the measurement dynamic ranges of the voltage acquisition devices, the detection dynamic range of the detection circuit can be maximized.

[0048] 4. The detection circuit sampling resistor R1 and the sampling resistor R2 of the present invention are independently connected to the amplifier A1 and the amplifier A2 respectively. The sampling resistor R1 and the sampling resistor R2 use the same performance parameters and models, and the amplifier A1 and the amplifier A2 use the same performance parameters and models, which reduces the inconsistency and nonlinearity caused by the amplifiers A1 and A2, thereby improving measurement accuracy.

[0049] 5. The detection circuit of the present invention has a compact structure, is easy to operate, has high reliability, and has low overall power consumption and high cost-effectiveness.

[0050] 6. The present invention has good scalability and can achieve a larger dynamic range by increasing the sampling resistor.

[0051] 7. The present invention has good versatility and can be applied to other current type detectors. BRIEF DESCRIPTION OF THE DRAWINGS

[0052] Figure 1 The circuit schematic diagram of the large-range detection circuit of the photoelectric detector output signal of the present invention;

[0053] Figure 2 It is a schematic diagram of voltage noise experimental data collected by voltage acquisition devices ADC1 and ADC2 in the large-range detection circuit of the photodetector output signal of the present invention. DETAILED DESCRIPTION

[0054] The technical solution of the present invention will be described clearly and completely below in conjunction with the accompanying drawings. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the technical solution in the present invention, all other embodiments obtained by ordinary technicians in the field without creative work are within the scope of protection of the present invention.

[0055] like Figure 1 As shown, a large-range detection circuit for output signals of a photodetector of the present invention comprises an amplifier A1, an amplifier A2, a voltage acquisition device ADC1, a voltage acquisition device ADC2, and a photodetector D1, a sampling resistor R1 and a sampling resistor R2 connected in series in sequence;

[0056] The photodetector D1 is arranged on the outgoing light path of the laser; its input end is connected to the external voltage V1;

[0057] The two input terminals of the amplifier A1 are respectively connected to the two ends of the sampling resistor R1, the negative electrode of the photodetector D1 is used to be connected to the external voltage V1, and the positive electrode of the photodetector D1 is connected to the sampling resistor R1;

[0058] The two input terminals of the amplifier A2 are respectively connected to the two ends of the sampling resistor R2, and the output terminal thereof is connected to the input terminal of the voltage acquisition device ADC2;

[0059] The other end of the sampling resistor R2 is grounded.

[0060] like Figure 1 As shown, the photodetector D1, the sampling resistor R1 and the sampling resistor R2 are connected in series in sequence, the negative electrode of the photodetector D1 is connected to the external bias voltage V1, the positive electrode of the photodetector D1 is connected to the sampling resistor R1, the end of the sampling resistor R2 facing away from the sampling resistor R1 is grounded, the sampling resistor R1 and the sampling resistor R2 are connected to the amplifier A1 and the amplifier A2 respectively, and the output voltages of the amplifier A1 and the amplifier A2 are transmitted to the voltage acquisition device ADC1 and the voltage acquisition device ADC2 respectively. Figure 2 As shown, it is a schematic diagram of voltage noise experimental data collected by voltage acquisition device ADC1 and voltage acquisition device ADC2 respectively.

[0061] Among them, the photodetector D1 adopts a photovoltaic indium gallium arsenide detector. Amplifier A1 and amplifier A2 are instrument amplifiers. The peak-to-peak value of the output noise of amplifier A1 is not greater than 5mV, and the maximum output voltage is not less than 10V; the peak-to-peak value of the output noise of amplifier A2 is not greater than 5mV, and the maximum output voltage is not less than 10V. The voltage acquisition device ADC1 is an oscilloscope or a data acquisition device; the voltage acquisition device ADC2 is an oscilloscope or a data acquisition device. The voltage acquisition device ADC1 can collect voltages in a range of not less than 0 to 10V; the voltage acquisition device ADC2 can collect voltages in a range of not less than 0 to 10V; the accuracy of the sampling resistor R1 is 1‰, and the accuracy of the sampling resistor R2 is 1‰.

[0062] The sampling ratio of the sampling resistor R1 and the sampling resistor R2 matches the dynamic range of the voltage acquisition device ADC1 and the voltage acquisition device ADC2, and the typical value of the sampling ratio is 500 to 5000. The sampling resistor R1 and the sampling resistor R2 are independently connected to the instrument amplifier A1 and the instrument amplifier A2 respectively.

[0063] The analog voltage signals output by the amplifier A1 and the amplifier A2 are transmitted to the voltage acquisition device ADC1 and the voltage acquisition device ADC2 respectively, so as to realize the acquisition of the voltage signals.

[0064] In addition, the present invention also provides a method for detecting a large-range output signal of a photoelectric detector D1, which comprises the following steps:

[0065] S1, setting circuit parameters, including external voltage V1, sampling resistor R1, sampling resistor R2, amplification factor G1 of amplifier A1, and amplification factor G2 of amplifier A2;

[0066] S1.1) Determine the minimum current Imin and the maximum current Imax output by the photodetector D1 according to the application requirements. Usually, Imax / Imin covers 5 to 6 orders of magnitude;

[0067] S1.2) Determine the external voltage V1 according to the reverse bias voltage that the photodetector D1 can withstand. Usually, the value is 12V;

[0068] S1.3) Estimate the resistance of the sampling resistor R1, the estimation method is: R1 = (V1-1) / Imax;

[0069] S1.4) According to the resistance estimation result of the sampling resistor R1 and the resistance accuracy requirement, the sampling resistor R1 is determined by checking the resistor nominal value table;

[0070] S1.5) Calculate the resistance of the sampling resistor R2, the calculation method is R2 = R1 / A;

[0071] S1.6) Calculate the gain G1 of amplifier A1, the calculation method is G1 = Vmin / (R1*Imin), where Vmin is twice the peak-to-peak value of the output voltage noise of amplifier A1;

[0072] Calculate the amplification factor G2 of the amplifier A2, the calculation method is G2 = Vmax / (R2*Imax), where Vmax is the maximum voltage that can be collected by the voltage collection device ADC2;

[0073] Wherein R1 / R2=Vmin / Vmax; the value of A is 1000; the value of Vmin is 10mV; the value of Vmax is 10V.

[0074] S2, connecting the voltage acquisition device ADC1 and the voltage acquisition device ADC2;

[0075] S3, applying an external voltage to the photodetector D1;

[0076] S4, when there is no laser irradiation on the photodetector D1, recording the voltage Vb1 collected by the voltage collection device ADC1 and the voltage Vb2 collected by the voltage collection device ADC2;

[0077] S5, when the photodetector D1 is irradiated with laser, the voltage Vo1 collected by the voltage collection device ADC1 and the voltage Vo2 collected by the voltage collection device ADC2 are recorded;

[0078] S6. Calculate the photocurrent Id output by the photodetector D1 when it is irradiated by laser.

[0079] S6.1) Calculate the output signal voltage Vs1 of ADC1, the calculation method is: Vs1 = Vo1 - Vb1;

[0080] S6.2) Calculate the output signal voltage Vs2 of ADC2, the calculation method is: Vs2 = Vo2 - Vb2;

[0081] S6.3) Determine the output voltage Vs of the detection circuit, the determination method is:

[0082] If Vs2≤10mV, then Vs=Vs1;

[0083] If Vs1>10V, then Vs=Vs2.

[0084] S6.4) Calculate the photocurrent Id output by the photodetector D1 when it is irradiated by laser. The calculation method is:

[0085] If Vs=Vs1, then Id=Vs / (G1*R1);

[0086] If Vs=Vs2, then Id=Vs / (G2*R2).

[0087] This embodiment uses a photovoltaic InGaAs photodetector commonly used in near-infrared light signal measurement. The wavelength of the laser irradiated to the photovoltaic InGaAs photodetector is 1070nm, which is in continuous output mode, and the laser power is from 2.5nW to 2.5mW. The spectral response range of the photovoltaic InGaAs photodetector is 0.9μm-1.7μm, the diameter of the photosensitive surface is 0.3mm, the response rate is 0.8A / W, and the tolerable reverse bias voltage is not less than 20V. The resistance values ​​of the sampling resistor 3 and the sampling resistor 4 are 5.1kΩ and 5.1Ω respectively. The amplification factors of the two amplifiers are both 1000 times, and the maximum voltage that can be collected by the two voltage acquisition devices is not less than 10V.

[0088] Based on the above photovoltaic InGaAs photodetector device, the specific steps of large dynamic range signal detection are as follows:

[0089] Step 1. Setting circuit parameters, including external voltage V1, sampling resistor R1, sampling resistor R2, amplification factor G1 of amplifier A1, and amplification factor G2 of amplifier A2;

[0090] Step 1.1. According to the laser power range reaching the photosensitive surface and the response rate of the photovoltaic InGaAs detector, determine that the minimum output current Imin of the photovoltaic InGaAs detector is 2.5nW*0.8A / W=2nA, and the maximum current Imax is 2.5mW*0.8A / W=2mA;

[0091] Step 1.2. According to the maximum reverse bias voltage that photovoltaic InGaAs can withstand, set the reverse bias voltage to 12V;

[0092] Step 1.3. Estimate the resistance of the sampling resistor R1, R1 = (12V-1V) / 2mA = 5.5kΩ;

[0093] Step 1.4. Check the resistor nominal value table and select R1 = 5.1kΩ;

[0094] Step 1.5. Calculate the resistance of the sampling resistor R2, R2 = R1 / 1000 = 5.1Ω;

[0095] Step 1.6. Calculate the gain G1 of amplifier A1, G1 = 10mV / (5.1kΩ*2nA) = 980;

[0096] Step 1.7. Calculate the gain G2 of amplifier A1, G2 = 10V / (5.1Ω*2mA) = 980;

[0097] Step 2. Apply an external voltage to the photodetector;

[0098] Step 3. When there is no laser irradiation on the photodetector, observe the voltage collected by the first group of voltage collection equipment, record the background voltage value Vb1 and the peak-to-peak value of the voltage noise Vpp1, and 2 times the peak-to-peak value of the voltage noise Vpp1 is the lower limit of the actual measurable voltage Vmin1 of the detection circuit. Based on Vmin1 and the amplification factor G1 of the first group of amplifiers and the resistance R1 of the first group of sampling resistors, the actual measurable minimum current Idmin can be calculated, and the calculation method is: Idmin = Vmin1 / (G1*R1); When there is no laser irradiation on the photodetector, observe the voltage collected by the second group of voltage collection equipment, and record its background voltage value Vb2 and the peak-to-peak value of the voltage noise Vpp2.

[0099] Step 4. Use laser to irradiate the photodetector, gradually increase the laser power irradiated to the photosensitive surface of the photodetector, observe the voltage Vo1 collected by the first group of voltage collection devices, when the voltage collected by the first group of voltage collection devices is less than 10V, based on the voltage collected by the first group of voltage collection devices and the amplification factor G1 of the first group of amplifiers and the resistance R1 of the first group of sampling resistors, the photocurrent size Id output by the photodetector can be calculated, and the calculation method is: Id = (Vo1-Vb1) / (G1*R1).

[0100] Step 5. Continue to increase the laser power irradiated on the photosensitive surface of the photodetector until the voltage collected by the first voltage collection device reaches saturation (reaching 10V). At this time, observe the voltage Vo2 collected by the second voltage collection device. When the voltage collected by the second voltage collection device is less than 10V, the photocurrent size Id output by the photodetector can be calculated based on the voltage collected by the second voltage collection device, the amplification factor G2 of the second amplifier, and the resistance value R2 of the second sampling resistor. The calculation method is: Id = (Vo2-Vb2) / (G2*R2).

[0101] Step 6. Continue to increase the laser power irradiated on the photosensitive surface of the photodetector until the voltage collected by the second voltage collection device reaches saturation (reaching 10V). Based on the amplification factor G2 of the second amplifier and the resistance value R2 of the second sampling resistor, the maximum current Idmax that can actually be measured can be calculated as follows: Idmax = (10V-Vb2) / (G2*R2).

Claims

1. A photoelectric detector output signal large range detection circuit, characterized in that: It includes an amplifier A1, an amplifier A2, a voltage acquisition device ADC1, a voltage acquisition device ADC2, and a photodetector D1, a sampling resistor R1 and a sampling resistor R2 which are connected in series in sequence; The photodetector D1 is arranged on the output light path of the laser; the cathode of the photodetector D1 is used to be connected to the external voltage V1, and the anode of the photodetector D1 is connected to the sampling resistor R1; The two input terminals of the amplifier A1 are respectively connected to the two ends of the sampling resistor R1, and the output terminal thereof is connected to the input terminal of the voltage acquisition device ADC1; The two input terminals of the amplifier A2 are respectively connected to the two ends of the sampling resistor R2, and the output terminal thereof is connected to the input terminal of the voltage acquisition device ADC2; The other end of the sampling resistor R2 is grounded.

2. The photoelectric detector output signal large-range detection circuit according to claim 1, characterized in that: The output noise peak-to-peak value of the amplifier A1 is not greater than 5mV, and the maximum output voltage is not less than 10V; The peak-to-peak value of the output noise of the amplifier A2 is not greater than 5mV, and the maximum output voltage is not less than 10V.

3. The photoelectric detector output signal large-range detection circuit according to claim 2, characterized in that: The photodetector D1 is a photovoltaic indium gallium arsenide detector; The amplifier A1 and the amplifier A2 are instrument amplifiers; The voltage acquisition device ADC1 and the voltage acquisition device ADC2 are both oscilloscopes or data acquisition devices.

4. The photoelectric detector output signal large-range detection circuit according to claim 3, characterized in that: The accuracy of the sampling resistor R1 and the sampling resistor R2 are both 1‰.

5. A method for detecting a large range of output signals of a photoelectric detector, characterized in that: The photoelectric detector output signal large-range detection circuit according to claim 1 comprises the following steps: S1, setting circuit parameters, the circuit parameters include external voltage V1, sampling resistor R1, sampling resistor R2, amplification factor G1 of amplifier A1, and amplification factor G2 of amplifier A2; S2, connecting the voltage acquisition device ADC1 and the voltage acquisition device ADC2; S3, applying an external voltage to the photodetector D1; S4, recording the voltage Vb1 collected by the voltage collection device ADC1 and the voltage Vb2 collected by the voltage collection device ADC2; S5, using laser to irradiate the photodetector D1, and recording the voltage Vo1 collected by the voltage collection device ADC1 and the voltage Vo2 collected by the voltage collection device ADC2; S6. Calculate the photocurrent Id output by the photodetector D1 when it is irradiated by laser.

6. The method for detecting a large range of output signals of a photoelectric detector according to claim 5, characterized in that: S1 is specifically: S1.1) Determine the minimum current Imin and the maximum current Imax output by the photodetector D1 according to application requirements; S1.2) determining an external voltage V1 according to the reverse bias voltage that the photodetector D1 can withstand; S1.3) Estimate the resistance value of the sampling resistor R1, the estimation method is R1 = (V1-1) / Imax; S1.4) determining the sampling resistor R1 according to the resistance estimation result of the sampling resistor R1 and the resistance accuracy requirement; S1.5) Calculate the resistance of the sampling resistor R2, the calculation method is R2 = R1 / A, the value of A is 1000; S1.6) Calculate the gain G1 of amplifier A1, the calculation method is G1 = Vmin / (R1*Imin), where Vmin is twice the peak-to-peak value of the output voltage noise of amplifier A1; The amplification factor G2 of the amplifier A2 is calculated as G2=Vmax / (R2*Imax), where Vmax is the maximum voltage that can be collected by the voltage collection device ADC2.

7. The method for detecting a large range of output signals of a photoelectric detector according to claim 6, characterized in that: The R1 / R2=Vmin / Vmax.

8. The method for detecting a large range of output signals of a photoelectric detector according to claim 7, characterized in that: The Vmin value is 10mV; The Vmax value is 10V.

9. The method for detecting a large range of output signals of a photoelectric detector according to claim 8, characterized in that: S6 is specifically: S6.1) Calculate the output signal voltage Vs1 of the voltage acquisition device ADC1, the calculation method is Vs1 = Vo1 - Vb1; S6.2) Calculate the output signal voltage Vs2 of the voltage acquisition device ADC2, the calculation method is Vs2 = Vo2 - Vb2; S6.3) Determine and determine the output voltage Vs of the detection circuit If Vs2≤10mV, then Vs=Vs1; If Vs1>10V, then Vs=Vs2; S6.4) Calculate the photocurrent Id output by the photodetector D1 when it is irradiated by laser. If Vs=Vs1, then Id=Vs / (G1*R1); If Vs=Vs2, then Id=Vs / (G2*R2).

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