CN210141940U

CN210141940U - Single photon detector and high-voltage rapid adjusting circuit thereof

Info

Publication number: CN210141940U
Application number: CN201920716059.9U
Authority: CN
Inventors: 陈水忠; 朱海博; 陈腾
Original assignee: Luoyang Institute of Electro Optical Equipment AVIC
Current assignee: Luoyang Institute of Electro Optical Equipment AVIC
Priority date: 2019-05-17
Filing date: 2019-05-17
Publication date: 2020-03-13
Anticipated expiration: 2029-05-17

Abstract

The utility model relates to a single photon detector and high-pressure quick adjustment circuit thereof, high-pressure quick adjustment circuit includes: the output end of the high-voltage circuit is used for outputting set voltage; a reference voltage circuit, the output end of which is used for generating a reference voltage; an operational amplifier; the non-inverting input end of the operational amplifier is connected with the output end of the reference voltage circuit, the output end of the operational amplifier is connected with the control end of the switching tube, the input end of the switching tube is connected with the output end of the high-voltage circuit, the output end of the switching tube is used for being connected with the cathode of the single-photon detection diode, and a capacitor is connected between the output end of the operational amplifier and the cathode of the single-photon detection diode in parallel. The utility model discloses can prevent that photodiode from puncturing, avoid ringing and oscillation problem, improve the stability of circuit.

Description

Single photon detector and high-voltage rapid adjusting circuit thereof

Technical Field

The utility model relates to a single photon detector, especially the high pressure quick adjustment circuit of its high pressure biasing device.

Background

Single photon detectors can be used in laser ranging systems. The method can improve the detection sensitivity of echo photons to a single photon level, and plays an important role in the ultra-long distance measurement fields of laser radar, earth-moon laser ranging, satellite laser ranging and the like.

To realize single-photon detection capability, the single-photon detector usually works in a geiger mode and has strong photoelectric conversion capability. When the target distance becomes smaller, the number of photons reflected from the target becomes larger, and the detector output current becomes larger. This makes the single photon detector in the geiger mode potentially burn out due to an excessive number of photons when detecting close range targets. Therefore, when the target distance is short, the bias voltage of the single photon detector needs to be rapidly reduced, so that the single photon detector works in a linear mode, and the photoelectric conversion capability of the single photon detector is weakened.

In order to achieve the above purpose, the single photon detector in the prior art is loaded with a reverse bias voltage in a manner as shown in fig. 1: for adjusting the single-photon detection diode D₂The detection capability of the system needs to be repeatedly adjusted by an upper computer or other modes_REFTo change V_HThe value of (c). In this way, if V_HToo large to be greater than D due to misoperation₂At a certain temperature at the maximum allowable reverse bias voltage, D₂Breakdown occurs in the reverse direction.

The CN207147641U publication number "a single photon detection-based bias voltage adjusting system" realizes the adjustment of the bias voltage through the operational amplifier and the feedback resistance network, and the feedback resistance network can adjust the amplification factor of the operational amplifier. In this way, the circuit will ring (a damped oscillation) or oscillate. Too much ringing can cause D₂Reverse breakdown; the oscillation may render the D2 and I-V conversion circuits inoperable; and large ripple, V_REFAnd V_HThe linear relationship of (a) is not good.

In conclusion, the circuit system in the prior art has poor stability and is easy to cause problems such as reverse breakdown.

SUMMERY OF THE UTILITY MODEL

An object of the utility model is to provide a single photon detector and high-pressure quick adjustment circuit thereof for solve the poor problem of circuit system stability of prior art.

In order to solve the technical problem, the utility model adopts the technical scheme that:

a high voltage fast regulation circuit comprising: the output end of the high-voltage circuit is used for outputting set voltage; a reference voltage circuit, the output end of which is used for generating a reference voltage; an operational amplifier; the non-inverting input end of the operational amplifier is connected with the output end of the reference voltage circuit, the output end of the operational amplifier is connected with the control end of the switching tube, the input end of the switching tube is connected with the output end of the high-voltage circuit, the output end of the switching tube is used for being connected with the cathode of the single-photon detection diode, and a capacitor is connected between the output end of the operational amplifier and the cathode of the single-photon detection diode in parallel.

The utility model also provides a single photon detector, including single photon detection diode, I-V converting circuit, and as above high-pressure quick adjustment circuit.

The capacitor of the utility model is a compensation capacitor, which can avoid the problem of ringing or oscillation of the circuit; the capacitor and the switch tube can have a certain effect of inhibiting ripples or high-frequency noise generated by the output end, so that the interference of the capacitor and the switch tube on the input end of the circuit is reduced, the offset voltage of the two input ends of the operational amplifier is reduced, the linear relation between the reference capacitor and the output voltage is increased, and the stability of the circuit is improved.

As a further improvement of a high-voltage quick adjusting circuit and a single-photon detector, the circuit is connected with a backward diode in parallel, and the anode of the backward diode is connected with the cathode of the single-photon detector. The reverse diode provides a bias voltage and a discharge current channel of the switch tube at the same time, and the reverse diode has a simple structure and an excellent effect.

As a further improvement of the high-voltage rapid regulating circuit and the single-photon detector, the switching tube is an MOS tube, the control end of the MOS tube is a grid electrode, the input end of the MOS tube is a drain electrode, and the output end of the MOS tube is a source electrode.

As a further improvement of the high-voltage rapid adjusting circuit and the single photon detector, the high-voltage circuit is a DC/DC boost circuit.

As a further improvement of the high-voltage rapid adjusting circuit and the single photon detector, the reference voltage circuit is composed of a digital-to-analog converter and an FPGA (field programmable gate array), or is composed of a low-dropout linear regulator and a resistance network.

Drawings

FIG. 1 is a prior art single photon detector DC bias circuit;

fig. 2 is a high voltage fast adjusting circuit of a single photon detector according to an embodiment of the present invention;

FIG. 3 is a view of embodiment D of the present invention₂A circuit state diagram of charging;

FIG. 4 shows an embodiment of the present invention D₂Circuit state diagram of discharge.

Detailed Description

The following description is made with reference to the accompanying drawings.

Single photon detector embodiment

As shown in FIG. 2, the single photon detector comprises a single photon detection diode D₂An I-V conversion circuit and a high-voltage quick regulation circuit. In the figure: single photon detection diode D₂Can be as follows: photomultiplier, superconductive nanowire single photon detector, avalanche photodiode. And the I-V conversion circuit is used for converting the current signal into a voltage signal so as to enable the detected single photon to generate an electric pulse for subsequent circuit processing.

The high-voltage rapid regulating circuit comprises a high-voltage circuit, a reference voltage circuit and an operational amplifier U₁MOS transistor Q₁Etc.; as another embodiment, MOS transistor Q₁Other types of switching tubes may be selected.

The high-voltage circuit is generally a DC/DC boost type circuit or module, outputting a voltage V_HTo an operational amplifier U₁And MOS transistor Q₁And (5) supplying power.

The reference voltage circuit consists of a digital-to-analog converter (DAC) and an FPGA, or a low dropout regulator (LDO) and a resistor network, and the output voltage is V_REF。

Operational amplifier U₁The non-inverting input end is connected with V_REFThe inverting input end is connected with a divider resistor R₁、R₂Operational amplifier U₁Output voltage V_GConnecting MOS tube Q₁Of the gate, MOS transistor Q₁Drain electrode of (2) is connected to V_HMOS transistor Q₁The source electrode of the single-photon detection diode D is connected with₂Of an operational amplifier U₁Output terminal of and single photon detection diode D₂A capacitor C1 is connected in parallel with the cathode, and a reverse diode D1 is connected in parallel with the capacitor C1. The anode of the reverse diode D1 is connected to the cathode of D2.

According to the working principle of MOS tube, single photon detecting diode D₂Reverse bias voltage V_B≈V_GThus an operational amplifier U₁According to input V_REFAdjustment D₂Cathode reverse bias voltage V_B. According to the principle of operational amplifiers, V_BIs determined by the following formula:

in this embodiment, V_HFixed after the circuit is powered on and less than D₂The maximum allowed reverse bias voltage at a certain temperature. If the misoperation causes V_REFLarger, loaded into D₂Cathode reverse bias voltage V_BBut always < V_H. Therefore, the embodiment of the utility model provides a can make single photon detector avoid puncturing because of the maloperation is reverse.

The working principle is as follows:

a: when V is increased_REFAt the time of voltage value, V_BIncrease, D₂And (6) charging. Suppose that D is at this time₂Is changing from the linear region to the geiger region. U shape₁The generated high-frequency current passes through C₁To D₂Quick charging; and D₁Cut-off, V_HBy Q₁Is provided to D₂Low frequency charging current, as shown by the dashed line in fig. 3. In this process, the I-V conversion circuit outputs a pulse having a width corresponding to the charging time. This pulse is a charging pulse and is not generally used as a useful signal.

B: when V is lowered_REFAt the time of voltage value, V_BDecrease of D₂And (4) discharging. Suppose that D is at this time₂Is being drivenThe geiger zone shifts to the linear zone. U shape₁The generated high-frequency current passes through C₁Low frequency current through D₁To D₂And a rapid discharge, as shown by the dashed line in fig. 4. C₁Injecting a pulse current into D₂Let D be₂The voltage rises rapidly.

When detecting the target, the number of target echo photons at a short distance is large, and D is rapidly reduced according to the principle B₂Cathode reverse bias voltage V_B. Thus, D₂The responsivity is reduced, the avalanche current is reduced, and the amplitude of the output pulse of the I-V conversion circuit is reduced. The number of target echo photons at a long distance is small, and D is rapidly increased by the principle of the A₂Cathode reverse bias voltage V_B. Thus, D₂The responsivity is improved, the avalanche current is increased, and the output pulse amplitude of the I-V conversion circuit is improved. According to the distance of the target, adjusting D₂Cathode reverse bias voltage V_BCan let D₂Working in a geiger zone to detect distant targets; and let D₂Working in linear region, detecting close-range targets while ensuring D₂And the optical fiber is not burnt out due to the increase of the number of near photons.

C in the present example₁In order to compensate the capacitor, the problem of ringing or oscillation of the circuit can be avoided; c₁And Q₁Can inhibit the ripples or high-frequency noises generated at the output end to a certain extent, which reduces the interference of the ripples or high-frequency noises on the input end of the circuit and reduces the operational amplifier U₁Offset voltage of two input ends increases V_REFAnd V_GThereby improving the stability of the circuit. In addition, in the embodiment, the current of the detector is provided by the power supply and is not limited by the operational amplifier.

In this example, D₁For at close range, is D₂Improve the fast discharge path of low frequency current and avoid D₂Overflowing; and at a long distance, providing Q₁The bias voltage of (1).

And an operational amplifier U₁MOS transistor Q₁The circuit of (2) forms an LDO-like structure, and can obviously inhibit ripples within 20 MHz. Furthermore, utilizeBroadband characteristics of the operational amplifier U1 such that the output voltage V_GThe swing amplitude of the high-voltage circuit is larger than the output voltage V of the high-voltage circuit_HThis enables loading at D₂Voltage V of_BThe rise time is shortened.

High voltage fast regulating circuit embodiment

The high-voltage fast adjusting circuit of this embodiment is the same as the high-voltage fast adjusting circuit in the single photon detector embodiments, and therefore, the details are not repeated.

Claims

1. A high voltage fast regulation circuit, comprising:

the output end of the high-voltage circuit is used for outputting set voltage;

a reference voltage circuit, the output end of which is used for generating a reference voltage;

an operational amplifier; the non-inverting input end of the operational amplifier is connected with the output end of the reference voltage circuit, the output end of the operational amplifier is connected with the control end of the switching tube, the input end of the switching tube is connected with the output end of the high-voltage circuit, the output end of the switching tube is used for being connected with the cathode of the single-photon detection diode, and a capacitor is connected between the output end of the operational amplifier and the cathode of the single-photon detection diode in parallel.

2. The high voltage fast regulation circuit of claim 1 wherein said capacitor is connected in parallel with a backward diode, the anode of said backward diode being connected to the cathode of said single photon detection diode.

3. The high-voltage fast regulating circuit according to claim 1 or 2, wherein the switching tube is an MOS tube, a control end of the MOS tube is a gate, an input end is a drain, and an output end is a source.

4. The high voltage fast regulation circuit of claim 1 or 2 wherein the high voltage circuit is a DC/DC boost type circuit.

5. The high-voltage fast regulating circuit according to claim 1 or 2, wherein the reference voltage circuit is composed of a digital-to-analog converter and an FPGA, or is composed of a low dropout linear regulator and a resistor network.

6. A single photon detector comprising a single photon detector diode, an I-V conversion circuit, and a high voltage fast regulating circuit as claimed in any one of claims 1 to 5.