Fiber array detection device for four-quadrant photodetector

Abstract

The application discloses a fiber array detection device for a four-quadrant photodetector, which comprises a body, a first end face and a second end face arranged in parallel along a first direction, and a side face extending along a second direction between the first end face and the second end face, wherein four V-shaped grooves arranged in parallel along the second direction are arranged on the side face; four optical fibers, which comprise a cylindrical optical fiber body and a protective layer wrapped on a part of the optical fiber body, and the part of the optical fiber body not wrapped by the protective layer is fixed in the V-shaped groove, and the protective layer is located on the side away from the body of the first end face; the part of the optical fiber body of the four optical fibers in the V-shaped groove is located on a concentric circle, and the distance between the part of the optical fiber body of the adjacent two optical fibers in the V-shaped groove is equal. The fiber array detection device for the four-quadrant photodetector can test the four quadrants of the four-quadrant photodetector simultaneously through the fiber array, improve the test precision, and improve the test efficiency.

Description

Technical Field

[0001] This invention belongs to the field of optoelectronic detection technology, specifically relating to a fiber array detection device for four-quadrant photodetectors, which is suitable for performance testing and calibration of four-quadrant photodetectors in systems such as laser guidance, optical alignment, and precision displacement measurement. Background Technology

[0002] A four-quadrant photodetector (4-QD) is a sensing element that uses four symmetrically distributed photosensitive regions to acquire the centroid position of a light spot in real time. Its output deviation signal can be directly used for closed-loop control, thus finding wide application in high-end fields such as laser guidance, optical tracking, precision alignment, aerospace attitude measurement, and laser communication acquisition and tracking. With the continuous advancement of weapon miniaturization and integration, the size of four-quadrant detector chips has shrunk from the millimeter level to the sub-millimeter level, and the quadrant gap has been reduced to the tens of micrometers level, posing unprecedented challenges to testing and calibration equipment.

[0003] In traditional processes, the performance testing of four-quadrant detectors generally employs a "quadrant-by-quadrant sequential testing" method: using a single optical fiber or focused laser beam, along with a two-dimensional electric displacement stage, the light spot is sequentially projected onto the center of each of the four quadrants. The current is recorded after each movement, and finally, parameters such as sensitivity, consistency, and crosstalk are obtained through algorithm fitting. While this method is simple in principle, it has the following limitations in engineering practice: it is difficult to achieve precise alignment with miniaturized four-quadrant detectors; the signal output strength is insufficient, affecting test accuracy; and the quadrant-by-quadrant sequential testing method results in testing times of several minutes for a single detector, making batch automated testing impossible.

[0004] In addition to the aforementioned core pain points, traditional methods also suffer from drawbacks such as poor environmental adaptability, excessive human intervention, and difficulties in data traceability. With the rapid proliferation of laser-guided weapons, miniaturized optoelectronic pods, and inter-satellite communication terminals, the annual demand for quadrant detectors has exceeded one million units, making the testing process a bottleneck in the entire industry chain. The industry urgently needs a more efficient testing device. Summary of the Invention

[0005] This invention provides a fiber optic array detection device for a four-quadrant photodetector to solve the technical problem of insufficient accuracy of traditional early warning methods mentioned above. Specifically, the technical solution is as follows:

[0006] A fiber optic array detection device for a four-quadrant photodetector, comprising:

[0007] The body includes a first end face and a second end face that are parallel to each other and extend along a first direction, and a side face that extends along a second direction and is located between the first end face and the second end face. The first direction is perpendicular to the second direction, and the side face is provided with four V-shaped grooves that are parallel to each other along the second direction.

[0008] Four optical fibers are respectively disposed in four V-grooves. Each optical fiber includes a cylindrical optical fiber body and a protective layer that wraps around a portion of the optical fiber body. The portion of the optical fiber body not wrapped by the protective layer is fixed to the V-groove. The protective layer is located on the side of the first end face away from the body, and the end of the protective layer closer to the body abuts against the first end face.

[0009] The fiber body portions of the four optical fibers located in the V-groove are located on concentric circles, and the distance between the fiber body portions of two adjacent optical fibers located in the V-groove is equal.

[0010] Furthermore, the body is a hollow tubular shape, and the body includes a first body part, a second body part, a first connecting part and a second connecting part that are spaced apart from each other between the first body part and the second body part;

[0011] The first inner side surface of the first body portion and the second inner side surface of the second body portion are parallel to each other. Two of the four V-shaped grooves are spaced apart on the first inner side surface of the first body portion, and the other two of the four V-shaped grooves are spaced apart on the second inner side surface of the second body portion.

[0012] Furthermore, the first connecting portion includes the upper connecting layer and the lower connecting layer, and the fiber array detection device for the four-quadrant photodetector also includes an intermediate aluminum foil heating layer. The first body portion, the upper connecting layer, the intermediate aluminum foil heating layer, the lower connecting layer and the second body portion are stacked sequentially.

[0013] Furthermore, the first body portion, the second body portion, the first connecting portion, and the second connecting portion are an integral structure. The first outer surface of the first connecting portion is formed with a serpentine groove etched by laser. Both ends of the serpentine groove extend to the first end face of the first connecting portion. Conductive wires are provided in the serpentine grooves. The conductive wires are formed by high-temperature sintering of conductive metal-glass composite slurry, wherein metal particles are embedded in the molten glass phase and metallurgically bonded to the sidewall of the serpentine groove to form an airtight, heat-resistant, and stable conductive body. The first outer surface of the first connecting portion is also covered with an insulating layer.

[0014] Furthermore, the body is a solid column, and the body includes two parallel first side surfaces and a second side surface. Two of the four V-shaped grooves are spaced apart on the first side surface, and the other two of the four V-shaped grooves are spaced apart on the second side surface.

[0015] Furthermore, the body comprises an upper body layer and a lower body layer, the first side is disposed on the upper body layer, the second side is disposed on the lower body layer, and the fiber array detection device for the four-quadrant photodetector further comprises an aluminum foil heating layer disposed between the upper body layer and the lower body layer.

[0016] Furthermore, the body is an integral structure, and the body also includes two parallel third side surfaces and a fourth side surface. A serpentine groove is formed on the third side surface by laser etching. Both ends of the serpentine groove extend to the first end surface. A conductive wire is provided in the serpentine groove. The conductive wire is formed by high-temperature sintering of a conductive metal-glass composite slurry, wherein metal particles are embedded in the molten glass phase and metallurgically bonded to the sidewall of the serpentine groove to form an airtight, heat-resistant and stable conductor. The third side surface is also covered with an insulating layer.

[0017] Furthermore, the material of the body is high borosilicate glass or monocrystalline silicon.

[0018] Furthermore, calculated from the center of the optical fiber body, the distance between the optical fiber body portions of two adjacent optical fibers located in the V-groove is half the diameter of the four-quadrant photodetector to be detected.

[0019] Furthermore, the free ends of the fiber bodies of the four optical fibers are formed with fused sphere lens portions, which are located on the side of the second end face away from the fiber body.

[0020] Furthermore, the fiber array detection device for the four-quadrant photodetector also includes an optical path isolation pad, which is disposed on the second end face of the main body. The optical path isolation pad has openings corresponding to the free ends of the fiber bodies of the four optical fibers, and the outer surface of the optical path isolation pad extends beyond the free ends of the fiber bodies of the optical fibers.

[0021] The fiber optic array testing device for four-quadrant photodetectors provided by this invention simultaneously tests all four quadrants of the photodetector using a fiber optic array, improving testing accuracy and efficiency. This invention arranges four optical fibers into a square with equal sides, mirroring the four photosensitive areas of the detector; all four areas are illuminated simultaneously upon placement, allowing for comprehensive data acquisition of sensitivity, consistency, and crosstalk without any platform movement. Motion is completely eliminated, reducing repeatability error to zero, shortening the testing cycle from minutes to seconds, and eliminating the need for time alignment in the algorithm, resulting in more stable results. The production line can operate continuously in a cryogenic chamber or vacuum chamber, achieving true batch automation while saving on precision displacement stages and their maintenance costs, significantly reducing overall costs.

[0022] The fiber optic array detection device for a four-quadrant photodetector provided by this invention incorporates aluminum foil or embedded heating wires. Upon power-up, the end face heats up within seconds, preventing frost formation. Simultaneously, the bare fiber end is fused into a spherical lens, converging the emitted beam and reducing stray light between quadrants. Furthermore, both the heating element and the lens are manufactured using existing production line equipment, requiring no additional optical components, resulting in almost zero cost increase. Continuous production is possible even in high and low temperature chambers during winter, eliminating the need for drying by opening the door, thus simultaneously improving testing efficiency and data reliability.

[0023] The fiber array detection device for four-quadrant photodetectors provided by this invention sets the center distance between adjacent fibers to the most frequently seen "universal spacing" in the market, so customers do not need to redesign the fiber array when changing models. Attached Figure Description

[0024] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0025] Figure 1 This is a schematic diagram of a first embodiment of a fiber optic array detection device for a four-quadrant photodetector according to the present invention;

[0026] Figure 2 This is a schematic diagram of the V-groove fixing clamp of the present invention;

[0027] Figure 3 This is a schematic diagram of the imaging of the fiber optic head end face according to the present invention;

[0028] Figure 4 This is a schematic diagram of the fiber optic array detection device for a four-quadrant photodetector and the testing of the four-quadrant photodetector according to the present invention.

[0029] Figure 5 This is a schematic diagram of a second embodiment of the fiber optic array detection device for a four-quadrant photodetector according to the present invention;

[0030] Figure 6 This is a schematic diagram of a third embodiment of the fiber optic array detection device for a four-quadrant photodetector according to the present invention;

[0031] Figure 7 This is a schematic diagram of the fourth embodiment of the fiber optic array detection device for a four-quadrant photodetector of the present invention;

[0032] Figure 8 This is a schematic diagram of the fifth embodiment of the fiber optic array detection device for a four-quadrant photodetector of the present invention;

[0033] Figure 9 This is a schematic diagram of another embodiment of the optical fiber of the present invention;

[0034] Figure 10 This is a schematic diagram of the optical path isolation pad of the present invention. Detailed Implementation

[0035] The embodiments of this application are described in detail below. Examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain this application, and should not be construed as limiting this application.

[0036] In the description of this application, unless otherwise expressly specified and limited, the terms "connected," "linked," and "fixed" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0037] In this application, unless otherwise expressly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature being directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature being directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0038] like Figure 1 The illustration shows a first embodiment of a fiber optic array detection device 100 for a four-quadrant photodetector according to this application, comprising: a body 10 and four optical fibers 20. Specifically, the body 10 includes a first end face 11 and a second end face 12 extending in parallel along a first direction, and a side surface extending in a second direction between the first end face 11 and the second end face 12, the first direction being perpendicular to the second direction. The side surface has four V-grooves 13 arranged parallel to the second direction. The four optical fibers 20 are respectively disposed in the four V-grooves 13. Each optical fiber 20 includes a cylindrical optical fiber body 21 and a protective layer 22 covering a portion of the optical fiber body 21. The portion of the optical fiber body 21 not covered by the protective layer 22 is fixed to the V-grooves 13. Preferably, the optical fiber body 21 is fixed to the V-grooves 13 with UV adhesive. The protective layers 22 are all located on the side of the first end face 11 away from the body 10, with the end of the protective layer 22 closest to the body 10 abutting against the first end face 11. The fiber bodies 21 of the four optical fibers 20, located in the V-grooves 13, are situated on concentric circles, with the distance between the fiber bodies 21 of adjacent optical fibers 20 in the V-grooves 13 being equal. This arranges the four optical fibers 20 into a square with equal sides, corresponding one-to-one with the four photosensitive areas of the four-quadrant detector. During testing, a single placement illuminates all four areas simultaneously, completing alignment and testing without any scanning. This square arrangement transforms traditional quadrant-by-quadrant scanning into parallel illumination of the four quadrants, reducing the testing cycle from minutes to seconds and eliminating micron-level alignment errors introduced by the motorized displacement stage, significantly improving batch automation efficiency.

[0039] In the first embodiment, the body 10 is a hollow tubular shape, comprising a first body portion 14, a second body portion 15, and a first connecting portion 16 and a second connecting portion 17 spaced apart between the first body portion 14 and the second body portion 15. The first inner surface of the first body portion 14 and the second inner surface of the second body portion 15 are parallel to each other. Two of the four V-grooves 13 are spaced apart on the first inner surface of the first body portion 14, and the other two of the four V-grooves 13 are spaced apart on the second inner surface of the second body portion 15. In this embodiment, four optical fibers 20 are disposed inside the body 10, which can improve the protection of the optical fibers 20. The hollow tubular structure hides the fragile optical fibers in the inner wall, which can prevent mechanical collisions and contamination during handling or frost formation in the cryogenic chamber, while maintaining a compact external size, facilitating direct docking with probe stations or high and low temperature chamber interfaces.

[0040] In the embodiments of this application, the body 10 is preferably made of borosilicate glass or monocrystalline silicon. Borosilicate glass is easy to process for the V-groove 13, and it has good affinity with UV adhesive, making the adhesive layer less prone to cracking after curing. It maintains its initial strength even after long-term high and low temperature cycling, requiring minimal maintenance. The material itself has ample market supply, mature slicing and polishing technology, and can be quickly implemented from small-batch prototyping to bulk procurement, resulting in low overall cost. The advantage of using monocrystalline silicon is that since quadrant chips are generally silicon-based, making the body 10 also monocrystalline silicon means it and the silicon-based quadrant chip are made of the same material, with identical thermal expansion and contraction curves. At low temperatures, there is no longer a pulling and dragging relationship; the relative positions of the end faces of the four optical fibers 20 and the photosensitive area of ​​the chip remain almost unchanged, further reducing quadrant consistency error. The material selection and the detector chip's matching strategy ensure that the relative displacement of the system is <0.1µm during the -40℃ to +85℃ cycle, further reducing quadrant consistency drift by 0.3%, providing higher pointing accuracy for high-end guided weapons.

[0041] In this embodiment, the distance between the portions of the fiber body 21 located in the V-groove 13 of two adjacent fibers 20, calculated from the center of the fiber body 21, is half the diameter of the four-quadrant photodetector to be tested. During positioning, the centers of the four fiber bodies 21 (the centers of the circumcircles of the four fiber bodies 21) correspond to the center (center) of the four-quadrant photodetector to be tested. In this embodiment, the distance between the portions of the fiber body 21 located in the V-groove 13 of two adjacent fibers 20 is 1.66 mm. This spacing is optimized for mainstream circular four-quadrant detector chips with a diameter of 3.32 mm, and the end faces of the four fibers are precisely positioned at 0.7R of the radius of the chip's photosensitive area (i.e., a ring 1.17 mm from the center). The 0.7R ring is the golden ring region for the responsivity of the four-quadrant detector. The light spot incident in this region can not only ensure independent light sensing in each quadrant, but also fill the quadrant gaps through edge scattering effect, reducing optical power crosstalk to below -25dB, which is better than the -20dB index of traditional center illumination.

[0042] This application describes an optional fabrication process for a fiber array detection device 100 used in a four-quadrant photodetector, taking the borosilicate glass body 10 as an example.

[0043] The single-mode fiber cladding diameter of this application is 125 μm. V-grooves 13 are cut into the surface of the borosilicate glass using a precision dicing machine. The groove width is 0.20–0.22 mm, the groove depth is 0.14–0.18 mm, the angle is 60°±1°, and the center-to-center distance between the two grooves is 1.66 mm. The fiber is cut to the required length, and the coating is removed using a thermal stripper. The bare fiber end is vertically cut with a fiber cleaver to make its end face flat, resulting in a 3–4 mm length of bare fiber. Figure 2As shown, the processed optical fiber is placed on the V-groove fixing fixture 200, and then the V-groove fixing fixture 13 is placed on the optical fiber axis-fixing stage. The V-groove fixing fixture 200 is adjusted for observation, and the CCD microscope is adjusted to clearly see the surface of the V-groove 13. The optical fiber 20 is pre-fixed after being placed in the V-groove 13. The bare optical fiber with the coating removed is then placed in the V-groove. (The text repeats itself here.) Figure 3 As shown, the CCD system images the fiber optic end face through a microscope. While adjusting the three axes of the alignment system, the CCD system observes the bare fiber 20 placed in the groove with the coating layer close to the edge of the V-groove 13. The fiber 20 is fixed in the middle of the V-groove 13, and the CCD system microscope image is adjusted. The cross-section of the fiber 20 is clearly seen in the center of the groove on the monitor. An appropriate amount of UV adhesive is dotted into the V-groove, and the UV adhesive is observed to be completely filled in the groove by the CCD system microscope. The UV spot irradiation lamp is turned on for exposure to pre-cur it. The above steps are repeated for the alignment of the next fiber. Then, the V-groove fixture 1000 is removed, and all the fibers 20 in the V-groove are aligned and subjected to UV exposure. After completion, they are removed from the alignment system stage. The aligned fiber V-groove fixing fixture 200 is assembled onto the grinding fixture. The fiber is protected during fiber array grinding and polishing to prevent wear and breakage. Coarse grinding, fine grinding, and polishing are performed sequentially. After polishing, the end face is inspected for flatness, no scratches, no damage, and good surface finish. Remove the fiber optic array and clean it with anhydrous ethanol using heat. Bond two 1.59mm thick borosilicate glass connectors between the two fiber optic arrays using UV adhesive. Position the four fiber cores 1.66mm apart in the center of each connector, forming an equidistant matrix component. (Example:) Figure 4 As shown, the fiber optic array is fixed to the four-quadrant photodetector 1000. Concentric holes are used to align and fix the end faces of the four fibers of the fiber optic array with the photosensitive areas of the four-quadrant photodetector 1000. Specifically, a pair of precision holes (usually two positioning pins) can be made on the fixing plate of the fiber optic array and the packaging shell of the four-quadrant detector at the same axis position. During assembly, the positioning pins are inserted into these two holes simultaneously, and the fiber end faces and the photosensitive areas of the chip are forcibly aligned without further adjustment.

[0044] This application discloses a fiber optic array testing device 100 for four-quadrant photodetectors, with a four-quadrant consistency error of <1.5%, a test repeatability deviation of <0.8%, and consistent optical power across all four end faces of the fiber optic array. The fiber optic array is suitable for testing miniaturized detectors, reducing testing time from minutes to seconds. It achieves precise alignment, full coverage of the photosensitive surface with parallel light spots, and enables automated batch testing.

[0045] like Figure 5The diagram shows a second embodiment of the fiber optic array testing device 200 for a four-quadrant photodetector according to this application. The same structures as in the first embodiment are represented by the same reference numerals. The difference from the first embodiment is that in this embodiment, the first connecting portion 160 includes an upper connecting layer 161 and a lower connecting layer 162. The fiber optic array testing device 200 for a four-quadrant photodetector also includes an intermediate aluminum foil heating layer 30. The first body portion 14, the upper connecting layer 161, the intermediate aluminum foil heating layer 30, the lower connecting layer 162, and the second body portion 15 are sequentially stacked. It is understood that in some cases, the four-quadrant photodetector under test needs to operate in an extremely low-temperature environment (e.g., −40°C), thus requiring the entire test platform to be moved into a low-temperature chamber. Cold, humid air instantly condenses into a thin frost on the fiber end face, scattering light and causing quadrant readings to drift, resulting in distorted test results. To avoid such situations, this embodiment incorporates an intermediate aluminum foil heating layer in the first connection section. Upon power-up, the end face heats up, preventing frost formation on the fiber optic end face and eliminating the hassle of repeatedly opening doors to clean the lens and realign. This ensures the reliability of test data under extremely cold conditions, providing a rapid and clean method for detector cryogenic acceptance. Specifically, the intermediate aluminum foil heating layer 30 can be a single aluminum foil resistive sheet, pre-coated with epoxy on both sides, and then sandwiched between two layers of high borosilicate glass (upper connection layer 161 and lower connection layer 162). After hot pressing, it forms a heating glass pad consisting of three pieces bonded together. This heating pad is identical in shape and size to the original pad, allowing for seamless replacement. Customers do not need to modify the fixture or cryogenic chamber interface, achieving a zero-replacement upgrade.

[0046] like Figure 6 The image shows a third embodiment of the fiber optic array detection device 300 for a four-quadrant photodetector according to this application. The difference from the first embodiment is that in this embodiment, the first body portion 14, the second body portion 15, the first connecting portion 16, and the second connecting portion 17 are an integral structure. Essentially, the body is formed by hollowing out a single piece of high borosilicate glass. Compared to the first embodiment, the distance between the first connecting portion 16 and the second connecting portion 17 in this embodiment is fixed. This avoids the instability caused by different thicknesses of adhesive when bonding the first connecting portion 16 and the second connecting portion 17 to the first body portion 14 and the second body portion 15 in the first embodiment, which would otherwise cause the center of the four optical fibers to deviate from the preset value of 1.66mm. The integral hollowed-out structure completely eliminates the accumulation of adhesive thickness tolerances, and the spacing between the four cores is determined at once by the V-groove, resulting in high stability over long-term use.

[0047] Specifically, in this embodiment, the first outer surface 161 of the first connecting portion 16 is formed with a serpentine groove (not shown) etched by laser. Both ends of the serpentine groove extend to the first end face 11 of the first connecting portion 16. Conductive wires (not shown) are provided inside the serpentine groove. The conductive wires are formed by high-temperature sintering of a conductive metal-glass composite paste, wherein metal particles are embedded in the molten glass phase and metallurgically bonded to the sidewall of the serpentine groove to form an airtight, heat-resistant, and electrically stable conductor. The conductive metal-glass composite paste can be silver particles plus lead-free glass. To improve the fluidity of the paste, a certain amount of organic carrier, such as terpineol plus ethyl cellulose, can also be added. Specifically, 70% silver particles plus 15% lead-free glass powder and 15% organic carrier can be used. The composite paste can be printed into the serpentine groove by screen printing. After drying in an oven, the organic carrier evaporates, leaving only the "silver + glass powder" solid skeleton inside the groove. After sintering at 550℃, the glass powder melts, wets the silver particles, and adheres to the trench walls. The silver particles are fused together to form a continuous conductive mesh. The high borosilicate glass is only annealed at this temperature, with no dimensional change. Simultaneously, both ends of the serpentine trench extend to the first end face of the first connection portion. Two conductive pads (not shown) are located on the first end face, away from the second end face, preventing interference between the optical fiber 20 and the tested four-quadrant photodetector 3000. The first outer surface of the first connection portion 16 is also covered with an insulating layer 40. Optionally, after sintering, a low-expansion epoxy is coated on the first outer surface 161 of the first connection portion 16, and after drying, the insulating layer 40 is formed. The buried resist sintering and glass annealing are completed in one step, without additional high-temperature cycling. The pads are placed on the end face away from the optical path to avoid metal volatilization contaminating the optical fiber end face, and the insulating epoxy layer further prevents short circuits caused by human touch.

[0048] like Figure 7 The image shows a fourth embodiment of the fiber optic array detection device 100' for a four-quadrant photodetector according to this application. The fiber optic array detection device 100' for a four-quadrant photodetector includes a first end face 11', a second end face 12', and V-grooves 13'. The difference from the first embodiment is that in this embodiment, the body 10' is a solid cylinder, comprising two parallel first side faces 14' and a second side face 15'. Two of the four V-grooves 13' are spaced apart on the first side face 14', and the other two are spaced apart on the second side face 15'. Compared to the first embodiment, this reduces structural complexity. Compared to the second embodiment, the V-grooves 13' are located on the periphery of the body 10', improving processing convenience. The solid cylinder structure eliminates the need for hollow cavity processing, and the side grooving can be completed using a standard planar laser head, eliminating the need for rotating fixtures and reducing tooling costs and processing speed.

[0049] In this embodiment, the body 101' is an integral structure. The body 101' also includes two parallel third side surfaces 16' and fourth side surfaces 17'. A serpentine groove formed by laser etching is formed on the third side surface 16'. Both ends of the serpentine groove extend to the first end surface 11'. Conductive wires are provided in the serpentine grooves. The conductive wires are formed by high-temperature sintering of conductive metal-glass composite paste. Metal particles are embedded in the molten glass phase and are metallurgically bonded to the sidewall of the serpentine groove to form an airtight, heat-resistant and stable conductor. The third side surface 16' is also covered with an insulating layer 40'.

[0050] like Figure 8 The image shows a fifth embodiment of the fiber optic array detection device 200' for a four-quadrant photodetector according to this application. The difference from the fourth embodiment is that in this embodiment, the body 101' includes an upper body layer 1011' and a lower body layer 2012', a first side 14' is disposed on the upper body layer 1011', and a second side 15' is disposed on the lower body layer 1012'. The fiber optic array detection device 200' for a four-quadrant photodetector also includes an aluminum foil heating layer 30' disposed between the upper body layer 1011' and the lower body layer 2012'.

[0051] like Figure 9 As shown in the embodiment of this application, the free ends of the fiber bodies 21' of the four optical fibers 20' are formed with fused ball lens portions 23', which are located on the side of the second end face away from the body. Optionally, the bare fiber can be inserted into a conventional optical fiber fusion splicer, and the end of the bare fiber can be melted by discharge, automatically shrinking into a spherical shape under the action of surface tension. After the discharge ends, the molten part solidifies within milliseconds, forming a smooth, crack-free spherical end face, which is the "fused ball lens". After the fusion is completed, the ball root still maintains a 125µm cylindrical shape and can be normally placed into the V-groove, with the ball suspended outside the groove. The fused ball lens reduces the fiber NA from 0.14 to 0.08, halves the output spot diameter, reduces the quadrant gap optical power by 3dB, and achieves collimation without additional microlenses, reducing system costs.

[0052] like Figure 10 As shown, the fiber optic array detection device for a four-quadrant photodetector also includes an optical path isolation pad 50. The optical path isolation pad is disposed on the second end face of the main body. The optical path isolation pad 50 has openings 51 formed on it, corresponding to the free ends of the four fiber bodies. The outer surface of the optical path isolation pad 50 extends beyond the free ends of the fiber bodies. The optical path isolation pad 50 is made of an opaque material. Sandwiched between the optical fibers, the optical path isolation pad 50 acts like a low wall, blocking lateral stray light and allowing each light to travel its own path. This prevents light emitted from the optical fibers from illuminating other quadrants of the four-quadrant photodetector, avoiding crosstalk between quadrants and resulting in more stable and accurate readings.

[0053] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the above embodiments do not limit the present invention in any way, and all technical solutions obtained by equivalent substitution or equivalent transformation fall within the protection scope of the present invention.

Claims

1. A fiber optic array detection device for a four-quadrant photodetector, characterized in that, Include: The body includes a first end face and a second end face that are parallel to each other and extend along a first direction, and a side face that extends along a second direction and is located between the first end face and the second end face. The first direction is perpendicular to the second direction, and the side face is provided with four V-shaped grooves that are parallel to each other along the second direction. Four optical fibers are respectively disposed in four V-grooves. Each optical fiber includes a cylindrical optical fiber body and a protective layer that wraps around a portion of the optical fiber body. The portion of the optical fiber body not wrapped by the protective layer is fixed to the V-groove. The protective layer is located on the side of the first end face away from the body, and the end of the protective layer closer to the body abuts against the first end face. The fiber body portions of the four optical fibers located in the V-groove are located on concentric circles, and the distance between the fiber body portions of two adjacent optical fibers located in the V-groove is equal. The body is a hollow tube, and the body includes a first body part, a second body part, a first connecting part and a second connecting part that are spaced apart from each other between the first body part and the second body part; The first inner side surface of the first body part and the second inner side surface of the second body part are parallel to each other. Two of the four V-shaped grooves are spaced apart on the first inner side surface of the first body part, and the other two of the four V-shaped grooves are spaced apart on the second inner side surface of the second body part. The first connecting part includes an upper connecting layer and a lower connecting layer, and the fiber array detection device for the four-quadrant photodetector also includes an intermediate aluminum foil heating layer. The first body part, the upper connecting layer, the intermediate aluminum foil heating layer, the lower connecting layer and the second body part are stacked in sequence.

2. The fiber optic array detection device for a four-quadrant photodetector according to claim 1, characterized in that, The first body part, the second body part, the first connecting part and the second connecting part are an integral structure. The first outer side of the first connecting part is formed with a serpentine groove etched by laser. Both ends of the serpentine groove extend to the first end face of the first connecting part. The serpentine groove is provided with a conductive wire. The conductive wire is formed by high-temperature sintering of conductive metal-glass composite paste. The metal particles are embedded in the molten glass phase and are metallurgically bonded to the sidewall of the serpentine groove to form an airtight, heat-resistant and stable conductor. The first outer side of the first connecting part is also covered with an insulating layer.

3. A fiber optic array detection device for a four-quadrant photodetector, characterized in that, Include: The body includes a first end face and a second end face that are parallel to each other and extend along a first direction, and a side face that extends along a second direction and is located between the first end face and the second end face. The first direction is perpendicular to the second direction, and the side face is provided with four V-shaped grooves that are parallel to each other along the second direction. Four optical fibers are respectively disposed in four V-grooves. Each optical fiber includes a cylindrical optical fiber body and a protective layer that wraps around a portion of the optical fiber body. The portion of the optical fiber body not wrapped by the protective layer is fixed to the V-groove. The protective layer is located on the side of the first end face away from the body, and the end of the protective layer closer to the body abuts against the first end face. The fiber body portions of the four optical fibers located in the V-groove are located on concentric circles, and the distance between the fiber body portions of two adjacent optical fibers located in the V-groove is equal. The body is a solid column, and the body includes two parallel first side surfaces and a second side surface. Two of the four V-shaped grooves are spaced apart on the first side surface, and the other two of the four V-shaped grooves are spaced apart on the second side surface. The body comprises an upper body layer and a lower body layer, the first side is disposed on the upper body layer, and the second side is disposed on the lower body layer. The fiber array detection device for the four-quadrant photodetector further comprises an aluminum foil heating layer disposed between the upper body layer and the lower body layer.

4. The fiber optic array detection device for a four-quadrant photodetector according to claim 3, characterized in that, The body is a single structure, and the body also includes two parallel third and fourth side surfaces. The third side surface has a serpentine groove formed by laser etching. Both ends of the serpentine groove extend to the first end surface. The serpentine groove contains conductive wires, which are formed by high-temperature sintering of conductive metal-glass composite paste. Metal particles are embedded in the molten glass phase and metallurgically bonded to the sidewall of the serpentine groove to form an airtight, heat-resistant and stable conductor. The third side surface is also covered with an insulating layer.

5. The fiber optic array detection device for a four-quadrant photodetector according to any one of claims 1 or 3, characterized in that, The body is made of borosilicate glass or monocrystalline silicon.

6. The fiber optic array detection device for a four-quadrant photodetector according to any one of claims 1 or 3, characterized in that, Calculated from the center of the optical fiber body, the distance between the optical fiber body portions of two adjacent optical fibers located in the V-groove is half the diameter of the four-quadrant photodetector to be detected.

7. The fiber optic array detection device for a four-quadrant photodetector according to any one of claims 1 or 3, characterized in that, The free ends of the fiber bodies of the four optical fibers are formed with fused sphere lens portions, which are located on the side of the second end face away from the fiber body.

Images