Array photoelectric converter, photoelectric conversion equipment and power supply system
By combining avalanche photodiodes and coupling capacitors with quenching resistors in the array photoelectric converter, the problem of poor applicability of photomultiplier tubes in narrow or magnetic field environments is solved, achieving efficient conversion of optical signals into electrical signals and improving signal quality and applicability.
Patent Information
- Application Number
- CN202511294250.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-09-11
- Publication Date
- 2025-12-12
AI Technical Summary
Existing photomultiplier tubes are difficult to operate in narrow or magnetic field environments, have poor applicability, and are difficult to efficiently convert weak light signals into measurable electrical signals.
An array photoelectric converter, including a conversion unit consisting of an avalanche photodiode, a coupling capacitor, and a quenching resistor, is used to convert light signals into current signals by triggering a chain reaction in the avalanche layer through illumination, and the signal output is optimized by the coupling capacitor and the quenching resistor.
It achieves efficient optical signal to current signal conversion in narrow or magnetic field environments, improves the signal rise slope and voltage amplitude, enhances the signal-to-noise ratio and signal strength, and reduces crosstalk rate.
Smart Images
Figure CN121126904A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the technical field of photoelectric conversion devices, and more specifically, to an array photoelectric converter, a photoelectric conversion device, and a power supply system. Background Technology
[0002] With the rapid development of extremely weak light detectors, they are widely used in fields such as nuclear medicine, high-energy physics, precision analysis, and laser detection and measurement. Currently, in order to efficiently convert weak light signals (even at the single-photon level) into measurable electrical signals, photomultiplier tubes (PMTs) are commonly used. These PMTs are based on the photoelectric effect and secondary electron multiplication. The photocathode absorbs photons to generate photoelectrons, which are then amplified by multiple stages of multiplier electrodes to output an electrical signal. However, these PMTs are difficult to operate in narrow or magnetic field environments, resulting in poor applicability. Summary of the Invention
[0003] One object of the present invention is to provide a new technical solution for an array photoelectric converter.
[0004] According to a first aspect of the present invention, an array photoelectric converter is provided, the array photoelectric converter comprising: At least one set of conversion units, wherein the first end of the conversion unit is connected to a common cathode and the second end of the conversion unit is connected to a common anode; The conversion unit includes an avalanche photodiode, a coupling capacitor, and a quenching resistor. The cathode of the avalanche photodiode serves as the first terminal of the conversion unit. The anode of the avalanche photodiode is connected to the first terminal of the quenching resistor. The second terminal of the quenching resistor serves as the second terminal of the conversion unit. The first terminal of the quenching resistor is connected between the anode of the avalanche photodiode and the first terminal of the coupling capacitor. The second terminal of the quenching resistor serves as the output terminal of the conversion unit.
[0005] Optionally, the avalanche photodiode includes a light incident layer, an intermediate layer, and an underlayer that are sequentially contacted, wherein the light incident layer serves as the cathode of the avalanche photodiode, and the underlayer serves as the anode of the avalanche photodiode. The intermediate layer forms an avalanche layer under the influence of the high reverse electric field of the light incident layer and the carrier migration driven by the bottom layer.
[0006] Optionally, each conversion unit in the array photoelectric converter is arrayed on a substrate, with the first end of each conversion unit extending to the first side of the substrate, the second end of each conversion unit extending to the second side of the substrate, and the output end of each conversion unit extending to the third side of the substrate; wherein the first side, the second side, and the third side of the substrate are different sides of the substrate.
[0007] Optionally, the substrate is disposed on the pad, and the pad is further disposed on the optical epoxy plastic seal, the pad and the optical epoxy plastic seal forming an encapsulation space to accommodate each of the conversion units.
[0008] Optionally, a first conductive via is provided on a first side of the substrate for passing through a first end of each of the conversion units, a second conductive via is provided on a second side of the substrate for passing through a second end of each of the conversion units, and a third conductive via is provided on a third side of the substrate for passing through the output end of each of the conversion units.
[0009] Optionally, the substrate is provided with anti-crosstalk physical gaps, which are disposed between adjacent conversion units on the substrate.
[0010] According to a second aspect of the present invention, a photoelectric conversion device is provided, the photoelectric conversion device comprising: An array photoelectric converter, wherein the array photoelectric converter is the array photoelectric converter described in the first aspect; A power supply, wherein the positive terminal of the power supply corresponds to the common anode of the array photoelectric converter, and the negative terminal of the power supply corresponds to the common cathode of the array photoelectric converter; A control circuit, wherein the first terminal of the control circuit is electrically connected to the control terminal of the power supply.
[0011] Optionally, the output terminal of the temperature detection circuit is electrically connected to the second terminal of the control circuit, the first terminal of the voltage feedback circuit is electrically connected to the negative terminal of the power supply, and the second terminal of the voltage feedback circuit is electrically connected to the third terminal of the control circuit. The control circuit is configured to control the voltage feedback circuit to adjust the DC voltage value output by the power supply circuit based on the operating temperature of the array photoelectric converter output by the temperature detection circuit.
[0012] Optionally, the photoelectric conversion device further includes a filter resistor and a filter capacitor. The filter resistor is connected across the first terminal of the conversion unit of the array photoelectric converter and the negative terminal of the power supply. The first terminal of the filter capacitor is connected between the filter resistor and the first terminal of the conversion unit, and the second terminal of the filter capacitor is grounded.
[0013] According to a third aspect of the present invention, a power supply system is provided, the power supply system comprising an array photoelectric converter or a photoelectric conversion device; Wherein, the array photoelectric converter is the array photoelectric converter described in the first aspect; the photoelectric conversion device is the photoelectric conversion device described in the second aspect.
[0014] According to one embodiment of this disclosure, by setting multiple sets of conversion units, each set of conversion units has an avalanche photodiode, a coupling capacitor, and a quenching resistor. When the conversion unit is exposed to light, the avalanche photodiode of the conversion unit can undergo a chain reaction, causing the avalanche current to rise sharply. Thus, under the premise that the avalanche photodiode can be used in narrow or magnetic field environments, the conversion of light signals to current signals is realized.
[0015] Other features and advantages of the invention will become clear from the following detailed description of exemplary embodiments of the invention with reference to the accompanying drawings. Attached Figure Description
[0016] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments of the invention and, together with their description, serve to explain the principles of the invention.
[0017] Figure 1 This is a circuit diagram of an array photoelectric converter according to an embodiment of this application.
[0018] Figure 2 This is a structural diagram of an array photoelectric converter according to another embodiment of this application.
[0019] Figure 3 This is a structural diagram of an array photoelectric converter according to another embodiment of this application.
[0020] Figure 4 This is a structural diagram of an array photoelectric converter according to another embodiment of this application.
[0021] Figure 5 This is an end view of a substrate according to another embodiment of this application.
[0022] Figure 6 This is a structural diagram of an array photoelectric converter according to another embodiment of this application.
[0023] Figure 7 This is a structural diagram of a photoelectric conversion device according to another embodiment of this application. Detailed Implementation
[0024] Various exemplary embodiments of the present invention will now be described in detail with reference to the accompanying drawings. It should be noted that, unless otherwise specifically stated, the relative arrangement, numerical expressions, and values of the components and steps set forth in these embodiments do not limit the scope of the invention.
[0025] The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit the invention or its application or use.
[0026] Techniques, methods, and equipment known to those skilled in the art may not be discussed in detail, but where appropriate, such techniques, methods, and equipment should be considered part of the specification.
[0027] In all the examples shown and discussed herein, any specific values should be interpreted as merely exemplary and not as limitations. Therefore, other examples of exemplary embodiments may have different values.
[0028] It should be noted that similar labels and letters in the following figures indicate similar items; therefore, once an item is defined in one figure, it does not need to be discussed further in subsequent figures.
[0029] An array photoelectric converter provided according to an embodiment of this application, such as Figure 1 As shown, the array photoelectric converter includes: At least one set of conversion units, with the first end of the conversion unit connected to a common cathode and the second end of the conversion unit connected to a common anode; The conversion unit includes an avalanche photodiode D1, a coupling capacitor C1, and a quenching resistor R1. The cathode of the avalanche photodiode D1 serves as the first terminal of the conversion unit. The anode of the avalanche photodiode D1 is connected to the first terminal of the quenching resistor R1. The second terminal of the quenching resistor R1 serves as the second terminal of the conversion unit. The first terminal of the quenching resistor R1 is connected between the anode of the avalanche photodiode D1 and the first terminal of the coupling capacitor C1. The second terminal of the quenching resistor R1 serves as the output terminal of the conversion unit.
[0030] In this embodiment, at least one set of conversion units can be 36 sets of conversion units. In each set of conversion units, the cathode of the avalanche photodiode (APD) is led out in parallel and connected to the anode through the quenching resistor R1 in series. The coupling capacitor C1 is led out from the anode of the avalanche photodiode D1 and connected in parallel to the output terminal of the conversion unit.
[0031] In this embodiment, when the avalanche photodiode D1 is exposed to light, a chain reaction occurs in the internal avalanche layer, causing the avalanche current to rise sharply, thereby realizing the conversion of optical signal to current signal.
[0032] In this embodiment, the function of the quenching resistor R1 is to generate a voltage drop across the quenching resistor R1 when the avalanche photodiode D1 undergoes avalanche breakdown. This causes the reverse bias voltage of the avalanche photodiode D1 to decrease. When the reverse bias voltage is lower than the critical value, the avalanche photodiode D1 is turned off, waiting for the next avalanche breakdown.
[0033] In this embodiment, the coupling capacitor C1 is used to suppress the zero-point offset caused by the reverse bias dark current, and at the same time reduce the increase in output capacitance caused by the parallel connection of multiple avalanche photodiodes D1, thereby improving the rise slope and voltage amplitude of the avalanche signal.
[0034] In this embodiment, the avalanche photodiode D1 arranged in the array is connected in parallel to the output terminal through the coupling capacitor C1, which can improve the total output gain of the array photoelectric converter and also increase the overall photosensitive window area.
[0035] In some embodiments, such as Figure 2 As shown, the avalanche photodiode D1 includes a light incident layer, an intermediate layer and an inner layer that are sequentially contacted. The light incident layer serves as the cathode of the avalanche photodiode D1, and the inner layer serves as the anode of the avalanche photodiode D1. Among them, the intermediate layer forms an avalanche layer under the influence of the high reverse electric field of the light incident layer and the carrier migration driven by the bottom layer.
[0036] In this embodiment, as Figure 2 As shown, the N+ layer of the avalanche photodiode D1 serves as the cathode and also as the light incident layer. The P+ layer of D1 is the bottom layer and also acts as the ion implantation layer, carrying the charge current. Between the P+ and N+ layers lies an unimplanted P-type semiconductor (i.e., the intermediate layer). Under a high reverse electric field, charge carriers in the N+ and P+ regions diffuse to form an avalanche layer. Under normal equilibrium conditions, the avalanche layer has no reverse avalanche current, only a weak dark current. When external light enters the N+ layer, a chain avalanche reaction occurs within the avalanche layer, causing the avalanche current generated by the external light to rise sharply. This current acts on the quenching resistor R1, generating a large voltage drop, causing the voltage across the avalanche layer to drop sharply. Simultaneously, the avalanche current generates an output optical signal through the coupling capacitor C1.
[0037] In some embodiments, each conversion unit in the array photoelectric converter is arrayed on the substrate 10, the first end of each conversion unit extends to the first side of the substrate 10, the second end of each conversion unit extends to the second side of the substrate 10, and the output end of each conversion unit extends to the third side of the substrate 10; wherein the first side, the second side, and the third side of the substrate 10 are different sides of the substrate 10.
[0038] In this embodiment, as Figure 3As shown, the array of conversion units can be arranged in a 6x6 configuration. The avalanche photodiodes D1 of each conversion unit are die-bonded to the substrate 10 using conductive silver paste. The common cathode of each conversion unit is connected to the substrate 10 via bonding wire S1. Coupling capacitors C1 are packaged between the avalanche photodiodes D1 using SMD technology and fixed to the substrate 10 using a low-temperature solder paste reflow soldering process. Quenching resistors R1 are packaged between the avalanche photodiode D1 wafers using SMD technology and fixed to the substrate 10 using a low-temperature solder paste reflow soldering process.
[0039] In this embodiment, by extending each end of each conversion unit to different sides of the substrate 10, it is easy for operators to identify each end of the conversion unit.
[0040] In some embodiments, the substrate 10 is disposed on the pad 20, and the pad 20 is further disposed on the optical epoxy plastic cover 40. The pad 20 and the optical epoxy plastic cover 40 form an encapsulation space to accommodate each conversion unit.
[0041] In this embodiment, a transparent optical epoxy plastic cover 40 is fixedly mounted on the substrate 10, which realizes circuit protection for the array photoelectric converter, while the optical signal can enter the packaging space normally.
[0042] In some embodiments, a first conductive via is provided on a first side of the substrate 10 for passing through a first end of each conversion unit, a second conductive via is provided on a second side of the substrate 10 for passing through a second end of each conversion unit, and a third conductive via is provided on a third side of the substrate 10 for passing through an output end of each conversion unit.
[0043] In this embodiment, as Figure 4 As shown, the cathode of the avalanche photodiode D1 is soldered to the conductive plane layer of the substrate 10 through conductive silver paste. At the same time, the upper and lower conductive lines and the substrate 10 are connected through the first conductive via, the second conductive via, and the third conductive via. The anode of the avalanche photodiode D1 is bonded to the lines of the substrate 10 through a bonding machine via a bonding line S1. The coupling capacitor C1 and the quenching resistor R1 are soldered to the substrate 10 through solder paste.
[0044] In this embodiment, as Figure 5As shown, the bottom of the substrate 10 has four SMD pads 20, each corresponding to one of the three conductive vias 30 (first, second, and third). The avalanche photodiode D1 is connected to the upper circuitry via these conductive vias. Specifically, pin 1' of one SMD pad 20 is connected to the cathode of the avalanche photodiode D1, pin 2' of one SMD pad 20 is connected to the anode of the avalanche photodiode D1, pin 3' of one SMD pad 20 is connected to the output terminal of the avalanche photodiode D1, and pin 4' of the other SMD pad 20 is left floating. These four SMD pads 20 enable the electrical connection between the array photoelectric converter and the motherboard.
[0045] In some embodiments, a crosstalk prevention physical gap 50 is provided on the substrate 10, and the crosstalk prevention physical gap 50 is disposed between adjacent conversion units on the substrate 10.
[0046] In this embodiment, an additional gap of more than 0.2 mm is added between adjacent avalanche photodiodes D1 to avoid crosstalk between different avalanche photodiodes D1. The signals between different avalanche photodiodes D1 are output through capacitive coupling. After capacitive isolation, the crosstalk signal strength is significantly reduced.
[0047] A photoelectric conversion device provided according to an embodiment of this application, such as Figure 7 As shown, the photoelectric conversion device includes: An array photoelectric converter, wherein the array photoelectric converter is any of the array photoelectric converters described above; Power supply 1, the positive terminal of power supply 1 corresponds to the common anode of the array photoelectric converter, and the negative terminal of power supply 1 corresponds to the common cathode of the array photoelectric converter. Control circuit 4, the first terminal of control circuit 4 is electrically connected to the control terminal of power supply 1.
[0048] In this embodiment, the power supply 1 can be a 100V high-voltage power supply. By providing a reverse bias voltage between the cathode and anode of the avalanche photodiode D1 in the array photoelectric converter using the 100V high-voltage power supply, the output signal, after being capacitively amplified, has a relatively small amplitude, making it difficult to achieve high-gain, high-signal-to-noise ratio photoelectric conversion through further amplification. Furthermore, an amplifier 5 is configured at the output of the conversion unit. After amplification, the intensity of the optical pulse signal is effectively improved, and the signal-to-noise ratio is also increased, thus achieving a lower crosstalk rate.
[0049] In some embodiments, the photoelectric conversion device further includes a temperature detection circuit 2 and a voltage feedback circuit 3; Among them, the output terminal of the temperature detection circuit 2 is electrically connected to the second terminal of the control circuit 4, the first terminal of the voltage feedback circuit 3 is electrically connected to the negative terminal of the power supply 1, and the second terminal of the voltage feedback circuit 3 is electrically connected to the third terminal of the control circuit 4. Among them, the control circuit 4 is set to control the voltage feedback circuit 3 to adjust the voltage value of the DC power output by the power supply circuit based on the operating temperature of the array photoelectric converter output by the temperature detection circuit 2.
[0050] In this embodiment, the temperature detection circuit 2 feeds back the operating temperature of the avalanche photodiode D1 of the array photoelectric converter to the control circuit 4. The control circuit 4 can automatically adjust the reverse bias voltage of the avalanche photodiode D1 through the voltage feedback circuit 3 to compensate for the reduction in avalanche voltage offset gain caused by the temperature change of the avalanche photodiode D1.
[0051] In some embodiments, the photoelectric conversion device further includes a filter resistor R2 and a filter capacitor C2. The filter resistor R2 is connected between the first terminal of the conversion unit of the array photoelectric converter and the negative terminal of the power supply 1. The first terminal of the filter capacitor C2 is connected between the filter resistor R2 and the first terminal of the conversion unit, and the second terminal of the filter capacitor C2 is grounded.
[0052] In this embodiment, by setting a filter resistor R2 and a filter capacitor C2, the filter resistor R2 and the filter capacitor C2 can play a filtering role to reduce the power supply noise of the power supply 1.
[0053] A power supply system according to an embodiment of this application includes an array photoelectric converter or a photoelectric conversion device; Wherein, the array photoelectric converter is the array photoelectric converter of any of the above embodiments; the photoelectric conversion device is the photoelectric conversion device of any of the above embodiments.
[0054] While specific embodiments of the invention have been described in detail by way of examples, those skilled in the art should understand that the examples are for illustrative purposes only and not intended to limit the scope of the invention. Those skilled in the art should understand that modifications can be made to the above embodiments without departing from the scope and spirit of the invention. The scope of the invention is defined by the appended claims.
Claims
1. An array photoelectric converter, characterized in that, The array photoelectric converter includes: At least one set of conversion units, wherein the first end of the conversion unit is connected to a common cathode and the second end of the conversion unit is connected to a common anode; The conversion unit includes an avalanche photodiode, a coupling capacitor, and a quenching resistor. The cathode of the avalanche photodiode serves as the first terminal of the conversion unit. The anode of the avalanche photodiode is connected to the first terminal of the quenching resistor. The second terminal of the quenching resistor serves as the second terminal of the conversion unit. The first terminal of the quenching resistor is connected between the anode of the avalanche photodiode and the first terminal of the coupling capacitor. The second terminal of the quenching resistor serves as the output terminal of the conversion unit. The avalanche photodiode includes a light incident layer, an intermediate layer, and an inner layer that are sequentially contacted. The light incident layer serves as the cathode of the avalanche photodiode, and the inner layer serves as the anode of the avalanche photodiode. The intermediate layer forms an avalanche layer under the influence of the high reverse electric field of the light incident layer and the carrier migration driven by the bottom layer.
2. The array photoelectric converter according to claim 1, characterized in that, The array of conversion units in the photoelectric converter is arranged on a substrate. The first end of each conversion unit extends to the first side of the substrate, the second end of each conversion unit extends to the second side of the substrate, and the output end of each conversion unit extends to the third side of the substrate. The first side, the second side, and the third side of the substrate are different sides of the substrate.
3. The array photoelectric converter according to claim 2, characterized in that, The substrate is disposed on the pads, and the pads are further provided with optical epoxy plastic caps. The pads and the optical epoxy plastic caps form an encapsulation space to accommodate each of the conversion units.
4. The array photoelectric converter according to claim 2, characterized in that, The first side of the substrate is provided with a first conductive via for passing through the first end of each of the conversion units, the second side of the substrate is provided with a second conductive via for passing through the second end of each of the conversion units, and the third side of the substrate is provided with a third conductive via for passing through the output end of each of the conversion units.
5. The array photoelectric converter according to claim 2, characterized in that, The substrate is provided with anti-crosstalk physical gaps, which are disposed between adjacent conversion units on the substrate.
6. A photoelectric conversion device, characterized in that, The photoelectric conversion device includes: An array photoelectric converter, wherein the array photoelectric converter is the array photoelectric converter according to any one of claims 1-5; A power supply, wherein the positive terminal of the power supply corresponds to the common anode of the array photoelectric converter, and the negative terminal of the power supply corresponds to the common cathode of the array photoelectric converter; A control circuit, wherein the first terminal of the control circuit is electrically connected to the control terminal of the power supply.
7. The photoelectric conversion device according to claim 6, characterized in that, The photoelectric conversion device also includes a temperature detection circuit and a voltage feedback circuit; The output terminal of the temperature detection circuit is electrically connected to the second terminal of the control circuit, the first terminal of the voltage feedback circuit is electrically connected to the negative terminal of the power supply, and the second terminal of the voltage feedback circuit is electrically connected to the third terminal of the control circuit. The control circuit is configured to control the voltage feedback circuit to adjust the DC voltage value output by the power supply circuit based on the operating temperature of the array photoelectric converter output by the temperature detection circuit.
8. The photoelectric conversion device according to claim 6, characterized in that, The photoelectric conversion device further includes a filter resistor and a filter capacitor. The filter resistor is connected between the first terminal of the conversion unit of the array photoelectric converter and the negative terminal of the power supply. The first terminal of the filter capacitor is connected between the filter resistor and the first terminal of the conversion unit, and the second terminal of the filter capacitor is grounded.
9. A power supply system, characterized in that, The power supply system includes an array photoelectric converter or a photoelectric conversion device; Wherein, the array photoelectric converter is the array photoelectric converter according to any one of claims 1-5; the photoelectric conversion device is the photoelectric conversion device according to any one of claims 6-8.