A balanced photodetector, a ranging device, and a velocity measuring device

Abstract

This application discloses a balanced photodetector, a ranging device, and a velocity measuring device to improve the duty cycle and achieve miniaturization. The balanced detector provided in this application includes: a first doped region, a second doped region, and a light-transmitting layer; the first and second doped regions are located on a first surface of the light-transmitting layer; the first doped region is used to receive a first optical signal on the first surface and output a first electrical signal corresponding to the first optical signal on a second surface opposite to the first surface; wherein, the first optical signal is one path of light output from a local oscillator light and a signal light via an optical mixer; the second doped region is used to receive a second optical signal on the first surface and output a second electrical signal corresponding to the second optical signal on a third surface opposite to the first surface; wherein, the second optical signal is another path of light output from a local oscillator light and a signal light via an optical mixer.

Description

Technical Field

[0001] This application relates to the field of photoelectric detection, and more particularly to a balanced photoelectric detector, a ranging device, and a velocity measuring device. Background Technology

[0002] Balanced photodetectors can be used in ranging, Doppler frequency shift velocities, and other scenarios to perform photoelectric conversion of measurement signals. A balanced photodetector includes a photosensitive area and output electrodes; the surface containing the photosensitive area is called a pixel. The ratio of the photosensitive area to the pixel area is called the duty cycle. With the same photosensitive area, a higher duty cycle results in a smaller overall pixel area, enabling miniaturization of the photodetector. Summary of the Invention

[0003] This application provides a balanced photodetector, a ranging device, and a velocity measuring device. These are used to increase the duty cycle and achieve miniaturization of the balanced photodetector, ranging device, and velocity measuring device.

[0004] In a first aspect, embodiments of this application provide a balanced photodetector, including a first doped region, a second dopant, and a light-transmitting layer. The first and second doped regions are located on a first surface of the light-transmitting layer. The first doped region receives a first optical signal from the light-transmitting layer on the first surface and outputs a first electrical signal corresponding to the first optical signal on a second surface opposite to the first surface. The first optical signal is a path of light output from a signal light and a local oscillator light after mixing by an optical mixer. The second doped region receives a second optical signal from the light-transmitting layer on the first surface and outputs a second electrical signal corresponding to the second optical signal on a third surface opposite to the first surface. The second optical signal is another path of light output from a signal light and a local oscillator light after mixing by an optical mixer.

[0005] In existing balanced photodetectors, a pixel includes a photosensitive area and an output electrode. However, in the balanced photodetector provided in this application, a first doped region and a second doped region receive light signals on a first surface. Therefore, the first surface is the plane where the photosensitive area of ​​the balanced photodetector is located, and also the plane where the pixel is located. The output surface of the electrical signal is on a second or third surface opposite to the first surface, not on the plane where the pixel is located. Therefore, no space needs to be reserved on the pixel for the output electrode. Thus, compared to existing balanced photodetectors, the area ratio of the photosensitive area on the pixel is increased, thereby improving the duty cycle. A higher duty cycle allows for a smaller pixel area while maintaining the same photosensitive area, thereby reducing the overall volume of the balanced photodetector and achieving miniaturization.

[0006] Furthermore, in this embodiment, the two doped regions are grown on the same material (transparent layer) to form an integrated structure, which significantly reduces the difficulty of assembling it with the optical system.

[0007] In one optional embodiment, a first doped region is included in a set of first doped regions on a first surface, and a second doped region is included in a set of second doped regions on the first surface. Multiple doped regions in the first doped region set and multiple doped regions in the second doped region set correspond one-to-one. Any doped region in the first doped region set is used to receive a third optical signal on the first surface and output an electrical signal corresponding to the third optical signal on a second surface opposite to the first surface. The second doped region set includes one doped region used to receive a fourth optical signal on the first surface and output an electrical signal corresponding to the fourth optical signal on a third surface opposite to the first surface. The third and fourth optical signals are different paths of light output from the local oscillator light and the signal light after mixing processing by an optical mixer.

[0008] In the balanced photodetector provided in this application embodiment, N pixels (doped regions) in the first linear detector array (first doped region set) and N pixels (doped regions) in the second linear detector array (second doped region set) form N pairs of balanced pixels. Each pair of balanced pixels is used to perform one-dimensional signal detection on the local oscillator light and the signal light output from the optical mixer, making the results of balanced photodetection more refined.

[0009] In one optional implementation, the signal light received by the multiple doped regions in the first set of doped regions comes from different fields of view of a single beam. This single beam is the output beam from the mixing of the original beam and the signal beam by an optical mixer.

[0010] In this embodiment, N pairs of pixels, consisting of the first set of doped regions and the second set of doped regions, are used to detect optical signals in different fields of view within a light beam. This refines the detection of a single beam of light in existing balanced photodetectors into the detection of different fields of view within that beam. This achieves a finer granularity of detection and improves the precision of the detection results.

[0011] In one optional embodiment, the first doped region includes a P-electrode and an N-electrode on the second surface, and the second doped region includes a P-electrode and an N-electrode on the third surface. The N-electrode on the first doped region is connected to the N-electrode on the second doped region. The P-electrode on the first doped region is used to output a first electrical signal, and the P-electrode on the second doped region is used to output a second electrical signal.

[0012] In the embodiments of this application, a common N-electrode design is adopted, which helps to improve the response consistency of balanced pixels. Compared with the method of independent N-electrodes for each pixel, the common N-electrode design can reduce the influence of the electrodes on the pixel duty cycle and improve the system's utilization of incident light.

[0013] In one optional embodiment, the first doped region further includes a hole transport material and an electron transport material. The P-electrode of the first doped region is connected to the hole transport material in the first doped region, and the N-electrode of the first doped region is connected to the electron transport material in the first doped region. The second doped region further includes a hole transport material and an electron transport material. The P-electrode of the second doped region is connected to the hole transport material in the second doped region, and the N-electrode of the second doped region is connected to the electron transport material in the second doped region.

[0014] In one alternative embodiment, the balanced photodetector further includes an isolation structure for isolating the first doped region and the second doped region.

[0015] On the photosensitive surface of this application embodiment, there is also a region not used for photosensitive purposes between the first doped region and the second doped region (such as...). Figure 5a As shown, the area between the two isolation structures on the first surface should include a region not used for photosensitive purposes. Compared to traditional single-pixel isolation structures designed to reduce signal crosstalk between adjacent effective pixels, the isolation structure in this embodiment can separate the effective pixel area (the area of ​​the first doped region and the area of ​​the second doped region on the first surface) from the non-pixel area (…). Figure 5a Isolation between the two isolation structures on the first surface of the image improves the response consistency between effective pixels inside and at the edges.

[0016] In one alternative embodiment, the balanced photodetector further includes a conduction structure for conducting the N-electrode of the first doped region and the N-electrode of the second doped region.

[0017] In one alternative embodiment, the balanced photodetector further includes a wiring substrate. A first electrode on the wiring substrate is connected to a P-electrode on a first doped region, and the first electrode is used to output a first electrical signal. A second electrode on the wiring substrate is connected to a P-electrode on a second doped region, and the second electrode is used to output a second electrical signal.

[0018] In this embodiment, a wiring substrate is used instead of wires or other connection methods to achieve the output of the first and second electrical signals. Compared to using wires or other methods, the connection structure is simpler, reducing the clutter of the wiring and thus lowering the system complexity and the probability of wire disconnection.

[0019] In one alternative embodiment, the material of the wiring substrate includes at least one of alumina, aluminum nitride, printed circuit board (PCB), and ceramic.

[0020] In one optional embodiment, the wiring substrate includes a third electrode and a fourth electrode, and a target trace connecting the third electrode and the fourth electrode. The third electrode is connected to the N-electrode of the first doped region, and the fourth electrode is connected to the N-electrode of the second doped region.

[0021] In this embodiment, the connection between the N-electrode of the first doped region and the N-electrode of the second doped region is achieved through the third electrode, the target trace, and the fourth electrode on the trace substrate. Compared to methods such as wires, the connection structure is simpler, reducing the clutter of the circuit connections, thereby reducing system complexity and the probability of circuit disconnection.

[0022] In one alternative implementation, the third and fourth electrodes are located inside or on the surface of the wiring substrate.

[0023] In one alternative implementation, the P-electrode on the first doped region is connected to a fifth electrode on the readout circuit board, and the P-electrode on the second doped region is connected to a sixth electrode on the readout circuit board. The readout circuit board is used to perform differential calculations based on a first electrical signal read from the fifth electrode and a second electrical signal read from the sixth electrode.

[0024] In one optional embodiment, both the first doped region and the second doped region include multiple P-electrodes, which are used to support a wiring substrate or a readout circuit board. Among the multiple P-electrodes in the first doped region, the first P-electrode is used to output a first electrical signal. Among the multiple P-electrodes in the second doped region, the second P-electrode is used to output a second electrical signal.

[0025] In this embodiment, multiple P electrodes are used to support the wiring substrate or readout circuit board, increasing the number of support points and reducing the force on each support point. This prevents deformation of the wiring substrate or readout circuit board due to excessive force at the support points, and avoids interruption of the connection with the P electrodes caused by deformation, ensuring that electrical signals can be output from the P electrodes.

[0026] Optionally, in addition to the P electrode, more support points can be set on the balanced photodetector to support the wiring substrate and readout circuit board; this is not limited here.

[0027] In one optional implementation, the balanced photodetector described in this application embodiment is a chip.

[0028] In one alternative implementation, both the first set of doped regions (the first linear detector array) and the second set of doped regions (the second linear detector array) are chips.

[0029] Secondly, embodiments of this application provide a ranging device, including an optical path unit, a calculation unit, and the balanced photodetector described in the first aspect. The optical path unit is used to acquire one light source and another light source as described in the first aspect, and the calculation unit is used to calculate the distance based on the first electrical signal and the second electrical signal described in the first aspect. The distance is the distance between the ranging device and the target object. The signal light in the first aspect is the light received by the ranging device after the light beam is projected from the ranging device onto the target object.

[0030] The beneficial effects of the second aspect are the same as those of the first aspect, and will not be repeated here. Since the ranging device provided in the second aspect is used to measure distance, and the balanced photodetector described in the first aspect can measure more precise and finer-grained electrical signals, the ranging device provided in the embodiments of this application can calculate more accurate distance results.

[0031] Thirdly, embodiments of this application provide a speed measuring device, including an optical path unit, a calculation unit, and the balanced photodetector described in the first aspect. The optical path unit is used to acquire one light source and another light source as described in the first aspect, and the calculation unit is used to calculate the speed based on the first electrical signal and the second electrical signal described in the first aspect. The speed is the relative speed between the ranging device and the target object. The signal light in the first aspect is the light received by the ranging device after the light beam is projected from the ranging device onto the target object.

[0032] The beneficial effects of the third aspect are the same as those of the first aspect, and will not be repeated here. Since the speed measuring device provided in the third aspect is used to measure speed, and the balanced photodetector described in the first aspect can measure more precise and finer-grained electrical signals, the speed measuring device provided in the embodiments of this application can calculate more accurate speed results. Attached Figure Description

[0033] Figure 1 This is a schematic diagram illustrating the application scenario of the balanced photodetector provided in the embodiments of this application;

[0034] Figure 2 A schematic diagram of the structure of a balanced photodetector provided in an embodiment of this application;

[0035] Figure 3 This is another structural schematic diagram of the balanced photodetector provided in the embodiments of this application;

[0036] Figure 4 This is another structural schematic diagram of the balanced photodetector provided in the embodiments of this application;

[0037] Figure 5a This is another structural schematic diagram of the balanced photodetector provided in the embodiments of this application;

[0038] Figure 5bA schematic diagram of the isolation structure provided in the embodiments of this application;

[0039] Figure 6 This is another structural schematic diagram of the balanced photodetector provided in the embodiments of this application;

[0040] Figure 7a This is another structural schematic diagram of the balanced photodetector provided in the embodiments of this application;

[0041] Figure 7b This is another structural schematic diagram of the balanced photodetector provided in the embodiments of this application;

[0042] Figure 8 This is another structural schematic diagram of the balanced photodetector provided in the embodiments of this application;

[0043] Figure 9a This is a schematic diagram illustrating another application scenario of the balanced photodetector provided in the embodiments of this application;

[0044] Figure 9b This is a schematic diagram illustrating another application scenario of the balanced photodetector provided in the embodiments of this application;

[0045] Figure 10a This is another structural schematic diagram of the balanced photodetector provided in the embodiments of this application;

[0046] Figure 10b This is another structural schematic diagram of the balanced photodetector provided in the embodiments of this application;

[0047] Figure 11 This is another structural schematic diagram of the balanced photodetector provided in the embodiments of this application;

[0048] Figure 12a This is another structural schematic diagram of the balanced photodetector provided in the embodiments of this application;

[0049] Figure 12b This is another structural schematic diagram of the balanced photodetector provided in the embodiments of this application;

[0050] Figure 13a A schematic diagram of the alignment marks of a balanced photodetector provided in an embodiment of this application;

[0051] Figure 13b Another schematic diagram of the alignment marks of the balanced photodetector provided in the embodiments of this application;

[0052] Figure 14 A schematic diagram of the ranging device provided in the embodiments of this application;

[0053] Figure 15 This is a schematic diagram of the speed measuring device provided in an embodiment of this application. Detailed Implementation

[0054] This application provides a balanced photodetector, a ranging device, and a velocity measuring device to increase the duty cycle and achieve miniaturization of the balanced photodetector and related equipment. Please refer to... Figure 1 , Figure 1 This is a schematic diagram illustrating an application scenario of the balanced photodetector provided in an embodiment of this application. For example... Figure 1 As shown, a laser emits a beam of light. A beam splitter splits this beam into two beams: one is used as the local oscillator beam input to the optical mixer, and the other is emitted through a transmitting optical module. The light emitted through the optical module is reflected by the target object and then received by the receiving optical module, serving as the signal beam input to the optical mixer. The optical mixer performs optical mixing on the local oscillator beam and the signal beam, outputting multiple beams. A balanced detector performs photoelectric conversion on at least two of these multiple beams, outputting the corresponding electrical signals for each of the at least two beams. Signal processing is then performed on these at least two electrical signals to obtain the distance between the ranging device and the target object.

[0055] It is worth noting that, Figure 1 This is merely one example of an application scenario for the balanced photodetector provided in this application embodiment. Besides this, the balanced photodetector provided in this application embodiment can also be applied to scenarios such as Doppler frequency shift velocities, and is not limited here.

[0056] Miniaturization is the development trend of balanced photodetectors. To achieve miniaturization of balanced photodetectors, it is necessary to increase the duty cycle of balanced photodetectors.

[0057] This application provides a balanced photodetector that uses a back-incident structure to place the photosensitive area and the electrodes on different planes. This structure reduces the encroachment of the electrodes on the photosensitive area of ​​the pixel, thereby increasing the proportion of the photosensitive area in the pixel, i.e., increasing the duty cycle.

[0058] Please see Figure 2 , Figure 2 This is a schematic diagram of a balanced photodetector provided in an embodiment of this application. The balanced photodetector 200 includes a light-transmitting layer 210, a first doped region 220, and a second doped region 230.

[0059] The first doped region 220 and the second doped region 230 are located on the first surface of the light-transmitting layer 210.

[0060] The first doped region 220 is used to receive a first optical signal from the light-transmitting layer 210 on the first surface and output an electrical signal corresponding to the first optical signal on the second surface opposite to the first surface. The first optical signal is a single optical path output by an optical mixer after mixing the local oscillator light and the signal light.

[0061] The second doped region 230 is used to receive the second optical signal from the light-transmitting layer 210 on the first surface and output an electrical signal corresponding to the second signal light on the third surface opposite to the first surface. The second signal light is another light output by the optical mixer after mixing the local oscillator light and the signal light.

[0062] In existing balanced photodetectors, the photosensitive area and the output electrode are on the same plane, meaning the area of ​​a pixel includes both the area of ​​the photosensitive area and the area of ​​the output electrode. In the balanced photodetector 200 provided in this application embodiment, the first doped region 220 and the second doped region 230 receive optical signals on a first surface. Therefore, the first surface is the photosensitive surface of the balanced photodetector 200 and also the plane where the pixel is located. The output surface of the electrical signal is on a second or third surface opposite to the first surface, not on the plane where the pixel is located. Therefore, no space needs to be reserved on the pixel for the output electrode.

[0063] like Figure 3 As shown in the bottom view, the portion of the first doped region 220 that contacts the first surface is the first photosensitive region; the portion of the second doped region 230 that contacts the first surface is the second photosensitive region. Both the first and second photosensitive regions are photosensitive regions of the balanced photodetector 200. Since the pixels of the balanced photodetector 200 include the first and second photosensitive regions but not the output electrode, the area ratio of the photosensitive region on the pixel is increased compared to existing balanced photodetectors, thereby improving the duty cycle.

[0064] Compared to existing balanced photodetectors, the balanced photodetector provided in this application embodiment has a higher duty cycle, thus resulting in a larger photosensitive area for the same pixel area. It can acquire more and more accurate data from the incident light beam, thereby improving the accuracy of the output electrical signal and increasing the types of output electrical signals.

[0065] With a higher duty cycle, the pixel area can be reduced while maintaining the same photosensitive area, thereby reducing the overall volume of the balanced photodetector and achieving miniaturization of the balanced photodetector.

[0066] based on Figure 2 or Figure 3 The structure shown can have P and N electrodes placed on the second and third surfaces to output corresponding electrical signals. Figure 4This is a schematic diagram of a balanced photodetector provided in an embodiment of this application. In this structure, the second surface of the first doped region 220 includes a P-electrode and an N-electrode, and the P-electrode of the first doped region 220 is used to output a first electrical signal. The third surface of the second doped region 230 includes a P-electrode and an N-electrode, and the P-electrode of the second doped region 230 is used to output a second electrical signal. Since the output terminal of the balanced photodetector is connected to a differential circuit, the N-electrode of the first doped region 220 and the N-electrode of the second doped region 230 are connected.

[0067] Optionally, the first doped region 220 includes an electron transport material and a hole transport material, with the P-electrode of the first doped region 220 connected to the hole transport material and the N-electrode connected to the electron transport material. The second doped region 230 also includes an electron transport material and a hole transport material, with the P-electrode of the second doped region 220 connected to the hole transport material and the N-electrode connected to the electron transport material.

[0068] Optionally, a medium may be included between the electron transport material and the hole transport material within the first doped region 220 to facilitate the migration of charge carriers (electrons or holes).

[0069] Optional, such as Figure 5a As shown, isolation between the first doped region 220 and the second doped region 230 can also be achieved through an isolation structure. For example... Figure 5b As shown, the isolation structure can be a box-shaped structure with a wall thickness. The interior of the isolation structure is used to carry the dielectric, hole transport material, and electron transport material. There are two through holes on the upper side (second or third side) of the isolation structure to conduct electricity between the material (electron transport material / hole transport material) inside the isolation structure and the electrodes (P electrode / N electrode) outside the isolation structure.

[0070] Optionally, the N-electrode of the first doped region 220 and the N-electrode of the second doped region 230 can be... Figure 5a The conductive structure shown is a connection. The conductive structure can be a metal plate, or it can be a wire, a trace on a trace board, or a trace on a readout circuit board, etc., which is not limited here.

[0071] Optional, such as Figure 6 As shown, the dielectric in the first doped region 220 and the second doped region 230 may include an absorber layer and a cap layer. A buffer layer is included below the absorber layer, and a dielectric layer is included above the cap layer. The first doped region 220 and the second doped region 230 also include an insulating material on the buffer layer and the cap layer. Figure 6 As shown, the dark gray buffer layer, insulating material, and dielectric layer together constitute an isolation structure used to isolate the first doped region 220 and the second doped region 230. The buffer layer, absorber layer, and cap layer can be formed using an epitaxial process.

[0072] At the top of the cap layer, there are electron transport materials and hole transport materials, which are used to connect the N electrode and the P electrode, respectively.

[0073] Optional, based on Figures 2 to 6 In addition to the structure shown in any of the embodiments, this application also provides an arrayed balanced photodetector structure for acquiring more refined output electrical signals, thereby improving the calculation accuracy and precision in scenarios such as ranging and Doppler frequency shift velocity measurement.

[0074] Please see Figure 7a The first doped region 220 is included in the first doped region set, and the second doped region 230 is included in the second doped region set. Both the first and second doped region sets contain N doped regions, and the N doped regions in the first doped region set correspond one-to-one with the N doped regions in the second doped region set.

[0075] The balanced photodetector provided in this application can be applied in scenarios such as ranging and Doppler frequency shift velocities. In these scenarios, distance can be calculated based on the electrical signals from different fields of view of the beam output by the optical mixer by photodetecting different fields of view. This application provides a balanced photodetector that achieves photodetection of different fields of view of the beam through an arrayed structure.

[0076] like Figure 7a As shown, the balanced photodetector 200 may include a first set of doped regions and a second set of doped regions. The first set of doped regions includes N doped regions, including the first doped region 220 in the aforementioned embodiment; the second set of doped regions includes N doped regions, including the second doped region 230 in the aforementioned embodiment.

[0077] In this embodiment, the first set of doped regions is also referred to as the first linear detector array, and the second set of doped regions is also referred to as the second linear detector array. Whether in the first set of doped regions or the second set of doped regions, the N doped regions are independent of each other and are used to detect different signals.

[0078] N pixels (doped regions) in the first linear detector array (first set of doped regions) and N pixels (doped regions) in the second linear detector array (second set of doped regions) form N pairs of balanced pixels.

[0079] Any doped region in the first set of doped regions is used to receive a third optical signal on a first surface and output an electrical signal corresponding to the third optical signal on a second surface opposite to the first surface. A doped region in the second set of doped regions corresponding to any of the aforementioned doped regions is used to receive a fourth optical signal on a first surface and output an electrical signal corresponding to the fourth optical signal on a third surface opposite to the first surface. The third and fourth optical signals are different paths of light output from the local oscillator light and the signal light after mixing by an optical mixer.

[0080] Optionally, in the balanced photodetector 200, the pixels in the first doped region set and the second doped region set can also be placed side by side, as shown in the specific structure. Figure 7b As shown.

[0081] like Figure 8 As shown, the first linear detector array (first set of doped regions) includes N doped regions, which constitute N pixels on the first surface. The second linear detector array (second set of doped regions) includes N doped regions, which constitute N pixels on the first surface. In this embodiment, a pixel is also referred to as a photodetector (PD) pixel.

[0082] The N pixels in the first linear detector array correspond one-to-one with the N pixels in the second linear detector array, forming N pairs of balanced pixels. Each pair of balanced pixels is used to perform one-dimensional signal detection on the local oscillator light and the signal light output from the optical mixer, making the results of balanced photoelectric detection more refined.

[0083] like Figure 9a As shown, the light itself and the signal light pass through an optical mixer, and the output beam is split by a polarizing beam splitter (PBS). Then, it passes through a half-wave plate and the PBS to obtain four beams I0, I... 90 I 180 I 270 Put I0 and I 180 As the input to the balanced photodetector 200, I0 and I are split by a beam splitter. 180 The circular light spot is divided into 16 parts, resulting in 16 fields of view. For example... Figure 9b As shown, the beams of I0's 16 fields of view are projected onto the 16 pixels of the first linear detector array via a beam splitter. 180 The 16 beams of light from the first field of view are projected onto 16 pixels of the second linear detector array. Among them, I0 and I... 180 The beams with the same field of view are projected onto the same pair of balanced pixels of the first linear detector array and the first linear detector array.

[0084] pass Figures 7a to 9b The structure shown can improve the point cloud output rate of the balanced photodetector. A higher point cloud output rate results in more accurate calculations. In this embodiment, N pairs of balanced pixels, composed of the first and second doped region sets, are used to detect light signals from different fields of view in the beam. This refines the detection of a single beam of light in existing balanced photodetectors into the detection of different fields of view within that beam. This achieves a refinement of the detection granularity and improves the precision of the detection results.

[0085] Optional, such as Figure 10a As shown, the balanced photodetector may also include a wiring substrate. A first electrode on the wiring substrate is connected to a P-electrode on the first doped region 220, and the first electrode is used to output a first electrical signal. A second electrode on the wiring substrate is connected to a P-electrode on the second doped region 230, and the second electrode is used to output a second electrical signal.

[0086] In this embodiment, a wiring substrate is used instead of wires or other connection methods to achieve the output of the first and second electrical signals. Compared to using wires or other methods, the connection structure is simpler, reducing the clutter of the wiring and thus lowering the system complexity and the probability of wire disconnection.

[0087] Optional, such as Figure 10b As shown, the wiring substrate may further include a third electrode and a fourth electrode, as well as a target trace connecting the third electrode and the fourth electrode. The third electrode is connected to the N-electrode of the first doped region 220, and the fourth electrode is connected to the N-electrode of the second doped region 230.

[0088] In this embodiment, the connection between the N-electrode of the first doped region and the N-electrode of the second doped region is achieved through the third electrode, the target trace, and the fourth electrode on the trace substrate. Compared to methods such as wires, the connection structure is simpler, reducing the clutter of the circuit connections, thereby reducing system complexity and the probability of circuit disconnection.

[0089] Optionally, the P electrode on the first doped region 220 can also be used with Figure 11 The electrode on one side of the wiring substrate or readout circuit board shown is connected, and the P electrode on the second doped region 230 can also be used to connect to the electrode on the other side of the readout circuit board. The readout circuit board is used to perform differential calculations based on a first electrical signal read from one electrode and a second electrical signal read from the other electrode.

[0090] Optional, such as Figure 12a and Figure 12bAs shown. Both the first doped region 220 and the second doped region 230 may include multiple P-electrodes. These multiple P-electrodes in the first doped region 220 and the second doped region 230 are used to support a wiring substrate or a readout circuit board. Specifically, among the multiple P-electrodes in the first doped region 220, the first P-electrode is used to output a first electrical signal. Among the multiple P-electrodes in the second doped region 230, the second P-electrode is used to output a second electrical signal.

[0091] In this embodiment, multiple P electrodes are used to support the wiring substrate or readout circuit board, increasing the number of support points and reducing the force on each support point. This prevents deformation of the wiring substrate or readout circuit board due to excessive force at the support points, and avoids interruption of the connection with the P electrodes caused by deformation, ensuring that electrical signals can be output from the P electrodes.

[0092] Optionally, in addition to the first doped region set and the second doped region set, multiple support points may be included, which are used to support the wiring substrate or readout circuit board.

[0093] Alternatively, the balanced photodetector 200 can be connected to the wiring substrate or readout circuitry via flip-chip bonding.

[0094] Optionally, during the production process of the balanced photodetector 200, a [device / device] can be set on the central axis of the first doped region set and the second doped region set. Figure 13a and Figure 13b The alignment marks shown are (Type C alignment marks). Mark 18 is used to mark the formation locations of the first and second doped regions, as well as the locations of the electron transport material and hole transport material on the first and second doped regions. Mark 19 is used to mark the locations of the P electrode and / or N electrode.

[0095] like Figure 13b As shown, preliminary registration can be achieved using the outer contour of the C-mark. Then, fine registration can be achieved using the inner contour of the C-mark.

[0096] In the embodiments of this application, by controlling the deviation of the alignment marks between the P electrode and / or N electrode and the junction region (first doped region and second doped region) during photolithography, the displacement and angular deviation between the two doped region arrays during the production process are reduced, and the photolithography operability is improved through the preliminary and fine two-step alignment of the marks.

[0097] like Figure 14 As shown in the figure, this application embodiment also provides a ranging device 300, including an optical path unit, a balanced photodetector, and a computing unit. The balanced photodetector is... Figures 2 to 12bThe balanced photodetector described in any embodiment. The optical path unit is used to acquire one light source and another light source input to the balanced photodetector, namely, one light source input to the first doped region set and another light source input to the second doped region set, or one light source input to the first doped region and another light source input to the second doped region. Wherein, one light source and another light source are... Figure 1 As shown, the local oscillator light and the signal light are output as two beams by the optical mixer. The signal light is the light received by the ranging device after the beam is projected from the ranging device onto the target object. The calculation unit is used to calculate the distance between the ranging device and the target object based on the first and second electrical signals output by the balanced photodetector.

[0098] As can be seen from the above embodiments, the balanced photodetector provided in this application provides a more accurate electrical signal result and a finer detection granularity. Therefore, the ranging device including this balanced photodetector can calculate a more accurate distance result based on the more accurate and finer-grained electrical signal.

[0099] like Figure 15 As shown, this application embodiment also provides a speed measuring device 400, including an optical path unit, a balanced photodetector, and a computing unit. The balanced photodetector is... Figures 2 to 12b The balanced photodetector described in any embodiment. The optical path unit is used to acquire one light source and another light source input to the balanced photodetector, namely, one light source input to the first doped region set and another light source input to the second doped region set, or one light source input to the first doped region and another light source input to the second doped region. Wherein, one light source and another light source are... Figure 1 As shown, the local oscillator light and the signal light are output as two beams by the optical mixer. The signal light is the light received by the velocity measuring device after the beam is projected from the ranging device onto the target object. The calculation unit is used to calculate the relative velocity between the ranging device and the target object based on the first and second electrical signals output by the balanced photodetector.

[0100] As can be seen from the above embodiments, the balanced photodetector provided in this application provides a more accurate electrical signal result and a finer detection granularity. Therefore, the speed measuring device including this balanced photodetector can calculate a more accurate speed result based on the more accurate and finer-grained electrical signal.

[0101] Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the specific working processes of the systems, devices, and units described above can be referred to the corresponding processes in the foregoing method embodiments, and will not be repeated here.

[0102] In the several embodiments provided in this application, it should be understood that the disclosed systems, apparatuses, and methods can be implemented in other ways. For example, the apparatus embodiments described above are merely illustrative; for instance, the division of units is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the coupling or direct coupling or communication connection shown or discussed may be an indirect coupling or communication connection between apparatuses or units through some interfaces, and may be electrical, mechanical, or other forms.

[0103] The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.

[0104] Furthermore, the functional units in the various embodiments of this application can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The integrated unit can be implemented in hardware or as a software functional unit.

[0105] If the integrated unit is implemented as a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, or all or part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of this application. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

Claims

1. A balanced photodetector, characterized by, The first doped region, the second doped region and the light-transmitting layer are included. The first doped region and the second doped region are located on a first surface of the light-transmitting layer. The first doped region is configured to receive a first optical signal on the first surface and output a first electrical signal corresponding to the first optical signal on a second surface opposite to the first surface; the first optical signal is one of optical signals output by a local oscillator light and a signal light through an optical mixer. The second doped region is configured to receive a second optical signal on the first surface and output a second electrical signal corresponding to the second optical signal on a third surface opposite to the first surface; the second optical signal is another of the optical signals output by the local oscillator light and the signal light through the optical mixer. The first doped region is included in a first doped region set on the first surface, the second doped region is included in a second doped region set on the first surface, a plurality of doped regions in the first doped region set correspond to a plurality of doped regions in the second doped region set one by one, the first doped region set is a first linear array of detectors, and the second doped region set is a second linear array of detectors. Any doped region in the first doped region set is configured to receive a third optical signal on the first surface and output an electrical signal corresponding to the third optical signal on the second surface opposite to the first surface. One doped region in the second doped region set is configured to receive a fourth optical signal on the first surface and output an electrical signal corresponding to the fourth optical signal on the third surface opposite to the first surface; the third optical signal and the fourth optical signal are different optical signals output by the local oscillator light and the signal light through the optical mixer.

2. The balanced photodetector of claim 1, wherein, The signal light received by the plurality of doped regions in the first doped region set is from different fields of view of the one optical signal.

3. The balanced photodetector of claim 1, wherein, The first doped region includes a P electrode and an N electrode on the second surface, and the second doped region includes a P electrode and an N electrode on the third surface. The N electrode on the first doped region is connected to the N electrode on the second doped region. The P electrode on the first doped region is configured to output the first electrical signal. The P electrode on the second doped region is configured to output the second electrical signal.

4. The balanced photodetector of claim 3, wherein, The first doped region further includes a hole transport material and an electron transport material; the P electrode of the first doped region is connected to the hole transport material in the first doped region, and the N electrode of the first doped region is connected to the electron transport material in the first doped region. The second doped region further includes a hole transport material and an electron transport material. The P electrode of the second doped region is connected to the hole transport material in the second doped region, and the N electrode of the second doped region is connected to the electron transport material in the second doped region.

5. The balanced photodetector according to any one of claims 1 to 4, wherein, The isolation structure is located between the first doped region and the second doped region, and is configured to isolate the first doped region and the second doped region. The conduction structure is configured to connect the N electrode of the first doped region and the N electrode of the second doped region.

6. The balanced photodetector according to any one of claims 1 to 4, wherein, The wiring substrate is further included. ​ 7. The balanced photodetector according to any one of claims 3 or 4, wherein, ​ The first electrode on the wiring substrate is connected with a P electrode on the first doped region, and the first electrode is used for outputting the first electrical signal; The second electrode on the wiring substrate is connected with a P electrode on the second doped region, and the second electrode is used for outputting the second electrical signal.

8. The balanced photodetector of claim 7, wherein, The wiring substrate comprises a third electrode, a fourth electrode, and a target wiring connecting the third electrode and the fourth electrode; The third electrode is connected with an N electrode of the first doped region; The fourth electrode is connected with an N electrode of the second doped region.

9. The balanced photodetector according to claim 8, wherein, a P electrode on the first doped region is used for connecting with a fifth electrode on a readout circuit board; a P electrode on the second doped region is used for connecting with a sixth electrode on the readout circuit board, and the readout circuit board is used for performing differential calculation according to the first electrical signal read from the fifth electrode and the second electrical signal read from the sixth electrode.

10. The balanced photodetector of claim 9, wherein, The first doped region and the second doped region each comprise a plurality of P electrodes; the plurality of P electrodes of the first doped region and the second doped region are used for supporting the wiring substrate or the readout circuit board; In the plurality of P electrodes of the first doped region, a first P electrode is used for outputting the first electrical signal; In the plurality of P electrodes of the second doped region, a second P electrode is used for outputting the second electrical signal.

11. The balanced photodetector according to any one of claims 1 to 4, wherein, The balanced photodetector is a chip.

12. A ranging device, characterized by The balanced photodetector according to any one of claims 1 to 11. The light path unit is used for obtaining one light and another light according to any one of claims 1 to 11. The calculation unit is used for calculating distance according to the first electrical signal and the second electrical signal according to any one of claims 1 to 11.

13. A speed measuring device, characterized by The balanced photodetector according to any one of claims 1 to 11. The light path unit is used for obtaining one light and another light according to any one of claims 1 to 11. The calculation unit is used for calculating speed according to the first electrical signal and the second electrical signal according to any one of claims 1 to 11.

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