Light source coupling automatic adjustment device and method

Abstract

The application belongs to the technical field of light source coupling, and aims at solving the problem of low light coupling precision in the prior art, and provides a light source coupling automatic adjusting device and method, which comprises the following steps: placing the optical center of a first reflector at an ellipsoid focal point position and placing the optical center of an adjustable focus objective at another ellipsoid focal point position; based on the initial position range of a second reflector; moving the position of the second reflector, based on the optical fiber coupling light power after light sequentially enters the optical fiber through the first reflector, the second reflector and the adjustable focus objective, adjusting the rotation angles of the two reflectors until the optical fiber coupling light power is maximized; then controlling the two reflectors to rotate by the same angle in the same direction, thereby adjusting the incident direction of the light beam incident to the center of the optical fiber until the optical fiber coupling light power is maximized to realize the axial incidence of the light beam along the optical fiber; and adjusting the focal length of the adjustable focus objective to complete focusing by aligning the light beam with the end face of the optical fiber.

Description

Technical Field

[0001] This invention belongs to the field of light source coupling technology, and particularly relates to an automatic adjustment device and method for light source coupling. Background Technology

[0002] The statements in this section are merely background information related to the present invention and do not necessarily constitute prior art.

[0003] In fields such as photonic chip packaging, fiber optic sensing systems, and high-power laser processing, efficient coupling between the light source and the coupled object is one of the core technological bottlenecks. With the development of light source technology, broadband and high-power infrared light sources are increasingly widely used, while the structural precision requirements of the coupled object are constantly increasing. Under this technological trend, the impact of coupling deviation on optical coupling efficiency is significantly amplified. These coupling deviations encompass multi-dimensional parameter deviations such as spatial position offset, angular tilt deviation, and phase matching deviation, which not only greatly increases the difficulty of controlling the coupling precision between the light source and the coupled object but also places higher technical demands on the stability of the coupling process.

[0004] Currently, the coupling adjustment between the light source and the coupled object mostly adopts traditional manual adjustment or simple closed-loop control schemes. Among them, the manual adjustment method mainly relies on the manual operation of a five-dimensional / three-dimensional precision adjustment stage. The operator completes the alignment operation between the light source and the coupled object by manually observing the changes in the reading of the optical power meter or observing the matching status of the optical image through a microscope. The simple closed-loop control scheme uses a single optical power signal as feedback, such as the conventional optical power threshold triggered unidirectional adjustment scheme. This scheme adjusts the axial position of the coupling component by a fixed step size to achieve basic coupling alignment between the light source and the coupled object.

[0005] However, the aforementioned traditional coupling adjustment schemes have many technical shortcomings in practical applications, making it difficult to meet the coupling requirements of high-precision, high-stability, and high-efficiency optical systems. Specifically, these shortcomings are reflected in the following aspects:

[0006] 1. The precision and consistency of the coupling adjustment are low.

[0007] Traditional adjustment relies on the operator's experience and feel, which makes it difficult to guarantee the control precision of coupling parameters (such as alignment accuracy, angle adjustment, spot spacing, etc.). The coupling effect varies greatly between different operators or between different batches of the same operator, and the coupling efficiency fluctuates significantly, which cannot meet the strict requirements of high-precision optical systems.

[0008] 2. The operation efficiency of coupling regulation is low.

[0009] Existing adjustment methods require repeated manual adjustments and data monitoring (such as power meter readings), as well as continuous adjustments to the mechanical structure. The whole process is cumbersome and time-consuming, especially in applications involving complex multi-channel coupling or micro-optical devices. A single adjustment may take several hours, making it difficult to meet the needs of mass production or rapid debugging.

[0010] 3. The stability and anti-interference ability of the coupled system are weak.

[0011] After manual adjustment, the mechanical structure is fixed by manual locking, which is easily affected by environmental vibration and temperature changes, causing the coupling position to shift. Moreover, it is impossible to monitor and compensate in real time, and the coupling efficiency will continue to decline during long-term operation, resulting in high subsequent maintenance costs.

[0012] In summary, developing a technical solution that can achieve high-precision, high-stability, and high-efficiency coupling and adjustment between the light source and the coupled object is a technical problem that urgently needs to be solved in fields such as photonic chip packaging, fiber optic sensing systems, and high-power laser processing. Summary of the Invention

[0013] To overcome the shortcomings of the prior art, this invention provides an automatic adjustment device and method for light source coupling. It achieves decoupling between the light angle and the position of the light spot, greatly improving coupling efficiency.

[0014] To achieve the above objectives, the present invention adopts the following technical solution:

[0015] In a first aspect, the present invention provides an automatic adjustment device for light source coupling, comprising: a focusable objective lens, a first reflector, a second reflector, a power detection module, a focusing platform, and a control terminal;

[0016] The optical center of the first reflecting mirror is located at one focus of the ellipsoid, and the optical center of the adjustable focusing objective lens is located at the other focus of the ellipsoid.

[0017] The control terminal is used to determine the initial position range of the second reflector based on the range of the incident angle of the light beam incident on the first reflector.

[0018] Based on the initial position range of the second reflector, the position of the second reflector is moved. Based on the fiber-coupled optical power of the beam after it enters the optical fiber through the first reflector, the second reflector and the adjustable focus objective lens, as fed back by the power detection module, the rotation angle of the first reflector and the second reflector is adjusted to change the incident position of the light spot on the end face of the optical fiber until the fiber-coupled optical power is maximized.

[0019] Then, the first and second reflectors are controlled to rotate in the same direction and at the same angle to ensure that the incident angle of the beam into the adjustable focus objective remains unchanged, thereby changing the incident position of the beam on the adjustable focus objective and adjusting the incident direction of the beam into the center of the optical fiber until the optical fiber coupling power is maximized and the beam is incident along the optical fiber axis.

[0020] The focusing platform is used to adjust the focal length of the adjustable objective lens so that the beam is aligned with the fiber end face to complete focusing.

[0021] Secondly, the present invention provides an automatic adjustment method for light source coupling, wherein the optical center of a first reflecting mirror is located at one focus of an ellipsoid, the optical center of an adjustable focusing objective lens is located at another focus of the ellipsoid, and the plane containing the second reflecting mirror is tangent to the ellipsoidal surface, comprising:

[0022] The initial position range of the second reflector is determined based on the range of the incident angle of the beam incident on the first reflector.

[0023] Based on the initial position range of the second reflector, the position of the second reflector is moved. Based on the fiber coupling power of the light beam after passing through the first reflector, the second reflector and the adjustable focus objective lens into the fiber, the rotation angle of the first reflector and the second reflector is adjusted to change the incident position of the light spot on the fiber end face until the fiber coupling power is maximized.

[0024] Then, the first and second reflectors are controlled to rotate in the same direction and at the same angle to ensure that the incident angle of the beam into the adjustable focus objective remains unchanged, thereby changing the incident position of the beam on the adjustable focus objective and adjusting the incident direction of the beam into the center of the optical fiber until the optical fiber coupling power is maximized and the beam is incident along the optical fiber axis.

[0025] Adjust the focal length of the adjustable lens to align the beam with the fiber end face and complete the focusing.

[0026] Thirdly, the present invention provides an electronic device including a memory and a processor, and computer instructions stored in the memory and running on the processor, wherein the computer instructions, when executed by the processor, perform the method described in the second aspect.

[0027] Fourthly, the present invention provides a computer-readable storage medium for storing computer instructions, which, when executed by a processor, perform the method described in the second aspect.

[0028] Fifthly, the present invention provides a computer program product, including a computer program that, when executed by a processor, implements the method described in the second aspect.

[0029] The above one or more technical solutions have the following beneficial effects:

[0030] This invention utilizes the spatial characteristics of an ellipsoid to determine the positional relationship of the device components and designs an automatically adjustable light source coupling device. This achieves the decoupling of the light angle and the position of the light spot, and clarifies the detailed adjustment process and calculation method. Compared with traditional manual adjustment, it greatly improves the coupling efficiency.

[0031] Advantages of additional aspects of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0032] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an improper limitation of the invention.

[0033] Figure 1 This is a schematic diagram of the automatic adjustment device for light source coupling in an embodiment of the present invention;

[0034] Figure 2 This is a schematic diagram of the beam angle between the adjustable focus objective and the fiber end face in an embodiment of the present invention;

[0035] Figure 3 This is a schematic diagram showing the incident and exit directions of the first and second reflecting mirrors in an embodiment of the present invention.

[0036] Figure 4 This is a schematic diagram of the scanning trajectory in an embodiment of the present invention;

[0037] Figure 5 This is a schematic diagram of a light beam incident on an optical fiber via an adjustable focusing objective lens in an embodiment of the present invention;

[0038] Figure 6 This is a schematic diagram showing the incident and exit directions of the first and second reflecting mirrors in an embodiment of the present invention.

[0039] Figure 7 This is a schematic diagram showing the adjustment of the rotation angles of the first and second reflecting mirrors in an embodiment of the present invention.

[0040] Figure 8 This is a schematic diagram of the first and second reflecting mirrors rotating in the same direction and at the same angle in an embodiment of the present invention.

[0041] Figure 9 This is a schematic diagram of the beam corresponding to the adjustable focus objective lens in an embodiment of the present invention. Detailed Implementation

[0042] It should be noted that the following detailed descriptions are exemplary and intended to provide further illustration of the invention. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains.

[0043] It should be noted that the terminology used herein is for the purpose of describing particular implementations only and is not intended to limit the exemplary implementations of the present invention.

[0044] Where there is no conflict, the embodiments and features in the embodiments of the present invention can be combined with each other.

[0045] Example 1

[0046] This embodiment discloses an automatic adjustment device for light source coupling, including: an adjustable focusing objective lens, a first reflecting mirror, a second reflecting mirror, a power detection module, and a control terminal;

[0047] The optical center of the first reflecting mirror is located at one focus of the ellipsoid, and the optical center of the adjustable objective lens is located at the other focus of the ellipsoid.

[0048] The control unit is used to determine the initial position range of the second reflector based on the range of the incident angle of the beam incident on the first reflector.

[0049] Based on the initial position range of the second reflector, the position of the second reflector is moved. Based on the optical fiber coupling power of the beam to be coupled after passing through the first reflector, the second reflector and the adjustable focus objective lens in sequence and entering the optical fiber, the rotation angle of the first reflector and the second reflector is adjusted to change the incident position of the light spot on the end face of the optical fiber until the optical fiber coupling power is maximized.

[0050] Then, the first and second reflectors are controlled to rotate in the same direction and at the same angle to ensure that the incident angle of the beam into the adjustable focus objective remains unchanged, thereby changing the incident position of the beam on the adjustable focus objective and adjusting the incident direction of the beam into the center of the optical fiber until the optical fiber coupling power is maximized and the beam is incident along the optical fiber axis.

[0051] The focusing platform is used to adjust the focal length of the adjustable lens so that the beam is aligned with the fiber end face to complete focusing.

[0052] This embodiment proposes an automatic light source coupling adjustment device that can automatically adjust the angle and position between the light source and the coupled object in multiple dimensions, thereby significantly improving coupling efficiency. Compared with traditional manual adjustment methods, the device in this embodiment can provide higher adjustment accuracy and stability in complex environments, while greatly improving operational efficiency, and can adapt to the needs of various working scenarios and environments.

[0053] By rationally arranging optical elements and utilizing the characteristics of ellipsoidal space, this embodiment achieves decoupling between the light angle and the spot position, making the light source coupling adjustment process more precise, faster, and more stable, thus meeting the requirements of modern optical systems for efficient, stable, and high-precision coupling.

[0054] The following is a detailed description of the automatic adjustment device for light source coupling proposed in this embodiment:

[0055] like Figure 1 As shown, the automatic adjustment device for light source coupling in this embodiment includes a light emitter, a collimating lens, a first reflector, a second reflector, a focusable objective lens, a beam splitter, a power detection module, a focusing platform, and a host computer control terminal; the first motor, the second motor, and the third motor are used to drive the first reflector, the second reflector, and the focusable objective lens, respectively.

[0056] The power detection module collects optical power data after the beam splitter has spun the optical fibers. This optical power data directly reflects the coupling effect between the beam and the optical fiber. The power detection module transmits the collected optical power data to the host computer control terminal, which serves as the basis for adjusting the reflector and the adjustable focus objective lens. The coupling efficiency is highest when the light spot is aligned with the center of the fiber end face, the beam is incident along the axial direction, and the focus is complete, and the corresponding optical power value reaches its peak. Once the host computer identifies the peak power, it will stop the automatic adjustment process.

[0057] The optical fiber is the target receiving object for the light source coupling. After the beam is calibrated by the adjustable focus objective lens, it will be split by a beam splitter (1:9). One path enters the power detection module, and the other path is transmitted to the optical fiber at the application end. The function of the optical fiber at the application end is to receive the precisely adjusted beam. The core objective of this embodiment is to enable the beam to be efficiently coupled into this optical fiber and improve the optical transmission efficiency.

[0058] Step 1: Adjust the beam to the center of the fiber end face, ensuring it enters the fiber at the optimal angle. Therefore, the position of the beam hitting a single point on the adjustable lens must remain constant, while the beam must be incident at different angles, causing the beam spot to move across the fiber end face until it hits the fiber core. This achieves the optimal angle.

[0059] like Figure 2 As shown, the beam hits the center point of the objective lens at a fixed position, the diameter of the fiber end face is d, and the distance from the objective lens to the fiber end face is... l The range of change in the incident beam angle is... for:

[0060] (1)

[0061] How can we ensure that the position of the beam incident on the center of the adjustable focusing objective remains constant while the incident angle changes? Based on the mathematical properties of the ellipsoid, the optical center of the first reflecting mirror is placed at one focus of the ellipsoid. Above, while the optical center of the adjustable objective lens is placed at another focal point. The plane containing the second reflecting mirror is tangent to the ellipsoid. When a beam of parallel light is incident on the first reflecting mirror and then reflected to a point on the ellipsoid (i.e., the center point of the second reflecting mirror), the beam will eventually originate from another focal point (i.e., the center point of the focusing objective). Launch.

[0062] To achieve precise control of the light spot's landing point on the fiber end face, it is first necessary to set the center of the second reflecting mirror to be located on the ellipsoid. Its coordinates satisfy the mathematical relation:

[0063] (2)

[0064] in, For the expression of the ellipsoid, For the semi-major axis, The half focal length is set;

[0065] Let be the expression for a line in a space with a fixed focus. A point on a straight line in the space of a fixed focus, i.e., a fixed focus , Let this be the direction vector of the line containing the beam of light that strikes a point on the end face of the optical fiber after two reflections. .

[0066] It can be from the center of the second reflecting mirror and focus Determined, that is:

[0067] (3)

[0068] Let the optical axis direction of the adjustable focusing objective be a unit vector. The angle between the x-axis and the positive x-axis is 135°, that is The direction vector of the line containing the beam This determines the direction in which the light beam is incident on the adjustable lens.

[0069] The angle between the incident light beam and the optical axis of the focusing objective lens δ From the derivation, we can obtain:

[0070] (4)

[0071] From formula (1), it can be seen that in order for the light spot to fall within the end face of the optical fiber, the following must be satisfied:

[0072] ,Right now

[0073] Where d is the diameter of the fiber end face.

[0074] Substitution The expression for the center of the second reflecting mirror. The following inequalities must be satisfied during the transformation:

[0075] (5)

[0076] The initial position range of the center of the second mirror must satisfy the condition of formula (5), and the optical center of the second mirror must be on the ellipsoid.

[0077] The center of the second reflecting mirror The corresponding equation of the tangent plane is:

[0078] (6)

[0079] Let the initial normal vector of the plane containing the first reflecting mirror be along the x-axis, denoted as . ,Pass and The straight line between two points is the incident line, passing through... and The straight line between the two points is the exit line; therefore, the magnitude of the exit direction vector can be calculated from this. The incident direction vector is: The emission direction is the direction away from the mirror: The difference between the outgoing and incoming directions allows us to find the unit normal vector that satisfies the law of reflection: Substituting and rearranging, we get:

[0080] (7)

[0081] The final normal vector is With the initial normal vector For reference, the first reflecting mirror first changes its pitch angle around a fixed y-axis. Then change the deflection angle around the fixed z-axis. Satisfying the relation:

[0082] , (8)

[0083] Solving for:

[0084] (9)

[0086] According to formula (6), let the initial normal vector of the plane where the second reflector is located be along the y-axis, and set it as... To change the equation of the tangent plane corresponding to the attitude of the second reflector, first change the pitch angle around a fixed x-axis. Then change the deflection angle around the fixed z-axis. After the above rotation, the unit normal vector of the plane containing the second reflecting mirror is... The component change is: the pitch angle changes around the x-axis. Initial normal vector The y component becomes The z component becomes To obtain the intermediate vector Change the deflection angle around the z-axis The y-component of the intermediate vector becomes The x component becomes z-components are preserved .

[0087] Finally, the unit normal vector of the plane containing the second mirror satisfies:

[0088] (10)

[0089] Find: ,therefore:

[0090] (11)

[0091] The normal vector of the plane containing the second mirror, and the gradient of the ellipsoid at the center point of the second mirror. If they are in the same direction, they need to be normalized to unit normal vectors first. .

[0092] Where the gradient components are: , , ,

[0093] Gradient magnitude:

[0094] Therefore, unit normal vector The components are:

[0095] (12)

[0096] Will Substituting into formula (11), we finally get:

[0097] (13)

[0098] The slope of the tangent, derived from the formula, is used to adjust and control the pitch angle of the first reflecting mirror via the first motor. Deflection angle Then, the second reflector is adjusted and controlled by the second motor to change to the corresponding position. 3D coordinates and pitch Deflection angle By changing the center of the second mirror Adjust the angle between the incident beam onto the adjustable objective lens and the optical axis. This changes the position of the light spot on the plane.

[0099] Make the light spot follow Figure 4 The scanning trajectory movement first scans a large area at a certain density. When the detection power reaches its maximum, it then scans a small area at a certain density, with that point as the center. When the power is at its maximum, the beam has moved to the center of the end face.

[0100] The specific process of the first step of adjustment is as follows: determine the range of incident beam angle change γ according to formula (1), and establish the pitch angle of the first reflecting mirror according to formulas (9) and (13). Deflection angle and the pitch angle of the second reflecting mirror Deflection angle With the coordinates P of the center of the second reflecting mirror The mapping relationship is as follows. By driving the first and second reflectors to the target angle by the first and second motors respectively, the light beam can be incident on the center of the adjustable focus objective lens at different angles, thereby forming a light spot on the end face of the optical fiber.

[0101] To achieve accurate scanning of the light spot on the fiber end face, a two-step search strategy is adopted:

[0102] First, large-scale coarse positioning:

[0103] Using the fiber end-face diameter d as a reference, the first movement step of the light spot on the fiber end-face is set to d / 10 to ensure complete coverage of the fiber end-face during the scanning process. Based on geometric relationships, the offset of the light spot relative to the center of the fiber end-face... r It satisfies the condition with the incident angle δ ,in, This is the distance from the adjustable-focus objective lens to the fiber optic end face. For each preset scanning position, according to the formula... Determine the beam incident angle corresponding to the preset scanning position. By traversing the possible positions of the optical center point P of the second reflecting mirror on the ellipsoid, the corresponding position of the current point P is calculated in real time. ,when and When the coordinates are consistent, it is considered that point P that can achieve the preset position has been found. Then, the required rotation angles of the first and second reflectors are calculated by formulas (9) and (13). The first and second reflectors are driven by the first and second motors respectively to reach the corresponding angles in sequence, and the fiber coupling power at the preset scanning position is recorded.

[0104] In such Figure 4For each preset scanning position of the spiral scanning trajectory shown, scanning is performed in the same manner as described above. The fiber coupling power is recorded at each landing point, and the coarse adjustment position corresponding to the maximum power value is obtained by comparison. ( The coarse adjustment position indicates that the light spot is close to the fiber core area.

[0105] Secondly, fine-tuning within a small area:

[0106] Coarse adjustment position Centered on the fiber, a two-dimensional scan is performed within the neighborhood using a second moving step size, while simultaneously monitoring power changes in real time. The second moving step size is set to 1 / 5 of the first moving step size in the coarse scan. When the fiber coupling power reaches its maximum value and no longer increases significantly with position changes, the beam is considered to be precisely aligned with the center of the fiber end face. The coordinates of the point are the optimal incident point, and the corresponding angle of the reflecting mirror ( 、 、 、 That is, the final target angle required for the first step.

[0107] Throughout the process, inequality constraints are used to ensure that the incident angle δ ≤ γ / 2, thereby guaranteeing that the light spot remains within the fiber endface and preventing scanning from exceeding the range. This method achieves rapid and accurate fiber endface alignment, laying the foundation for the subsequent second step of adjusting the axial incidence.

[0108] Step 2: At this point, although the beam is aligned with the center of the fiber, it will be incident on the fiber at an angle. It is necessary to ensure the beam is incident along the fiber's axial direction. For example... Figure 5 It can be seen that by keeping the incident angle of the beam hitting the adjustable focus objective constant, and changing the position of the beam landing point on the mirror surface, the incident direction entering the center of the optical fiber can be changed, so that the beam is incident along the optical fiber axis.

[0109] According to the law of reflection, the angle of reflection equals the angle of incidence. Figure 6 As shown, the incident angle of the incident beam hitting the first planar reflecting mirror is... The angle of incidence after reflection that hits the second plane mirror is The angle between the normals of the two mirrors is And there is a relationship Then, the angle between the incident direction and the exit direction of the beam is obtained based on geometric relationships. for:

[0110] (14)

[0111] like Figure 6As shown, if the first reflecting mirror rotates in one direction Angle, if the second reflecting mirror also rotates in that direction Angle, which is the angle between the normals of the two mirrors after rotation. for:

[0112] (15)

[0113] like Figure 7 As shown, from formulas (14) and (15), it can be seen that after the beam undergoes two reflections, the angle between the incident direction and the exit direction is... Only with Regarding the first and second reflecting mirrors rotating in the same direction and with rotation angles satisfying the following... hour, That is, after the light beam is reflected by the two mirrors, the angle between the incident direction and the exit direction remains unchanged.

[0114] Taking the XOY plane as an example, based on the results obtained in the first step, the optical path length of the light beam between the first and second reflecting mirrors is... The optimal exit angle of the second reflecting mirror is At this time, the angle between the normal to the plane containing the first reflecting mirror and the normal to the plane containing the second reflecting mirror is . When the first and second reflecting mirrors deflect in the same direction When the angle is right, according to the law of sines, first calculate the distance the light spot on the second reflecting mirror 2 has moved. :

[0115] (16)

[0116] Simplifying, we get:

[0117] Calculated using formula (16) Then, using the law of sine, the distance the light spot moves in the horizontal direction of the objective lens can be calculated. for:

[0118] (17)

[0119] Solving for:

[0120] The principle of the XOZ plane is the same as above; the angle between the normal to the plane containing the first reflector and the normal to the plane containing the second reflector is... When the first and second reflecting mirrors are tilted in the same direction at different angles... At that time, the distance the light spot moves in the vertical direction of the objective lens for:

[0121] Solving for: (18)

[0122] The pitch and deflection angles of the first and second reflectors are controlled by a motor drive, while simultaneously maintaining the first and second reflectors rotating by the same angle in the same deflection direction. Rotate by the same angle in the same pitch direction The power reaches its maximum, indicating that the beam has been incident orthogonally along the fiber optic axis.

[0123] The specific adjustment method for the second step is as follows:

[0124] First, large-area coarse positioning: drive the two mirrors synchronously with a large displacement step size, so that the light spot moves in the horizontal and vertical directions of the objective lens, scanning and covering the entire objective lens aperture.

[0125] To ensure scanning resolution and prevent the light spot from exceeding the objective lens boundary, the first displacement step size is taken as 1 / 10 of the diameter of the adjustable focusing objective lens, and the target displacement step size is... The first and second reflectors are driven by the first and second motors to traverse the possible rotation angles. For each candidate rotation angle, the corresponding actual spot movement distance is calculated using formulas (17)-(18). ,when and When the rotation angle is consistent or within the allowable error range, determine the standard driving amount of the current target displacement step and record the fiber coupling power after adjustment under the combination of rotation angles.

[0126] The fiber coupling power is recorded at each landing point, and the coarse rotation angle combination corresponding to the maximum fiber coupling power is obtained by comparison. After adjusting this coarse rotation angle combination, it indicates that the beam has approached the center of the fiber end face, but the incident direction may still have a deviation.

[0127] Then, fine-tuning is performed within a small range. Centered on the coarse rotation angle combination, a two-dimensional scan is conducted in the neighborhood using a second displacement step size, while simultaneously monitoring changes in fiber coupling power. The second displacement step size is set to 1 / 5 of the first displacement step size in the coarse adjustment. When the fiber coupling power reaches its maximum value and no longer increases significantly with changes in angle, it is considered that the beam has been incident normally along the fiber axis, and at this point, the optical coupling power value is globally maximum.

[0128] By constraining the angle range, the light spot is ensured not to exceed the objective lens boundary, thus avoiding light energy loss. This method achieves fast and accurate automatic alignment and is suitable for the initialization and optimization of fiber optic coupling systems.

[0129] According to the adjustment method, the pitch and deflection angles of the first and second reflectors are controlled by the first and second motors, while keeping the first and second reflectors rotating by the same angle in the same deflection direction. Rotate by the same angle in the same pitch direction After fine-tuning within a small range, the power reaches its maximum, indicating that the beam has been incident normally along the fiber optic axis.

[0130] Step 3: Focusing. Based on the optimal receiving angle relationship of a single-mode fiber for a light beam, adjust the focal length of the adjustable objective lens so that the beam waist is located at the fiber end face, and the beam waist intensity and mode intensity match and coincide. Simultaneously focus to maximize the beam's penetration into the fiber core.

[0131] Optimal reception angle of single-mode fiber for beam for:

[0132] (19)

[0133] in, The diameter of the fiber mode field. λ is the wavelength of the light beam.

[0134] Based on the optimal receiving angle of the beam in single-mode fiber The third motor drives and controls the adjustment of the focal length of the adjustable objective lens, and then the motor adjusts and controls the movement of the optical fiber axis to align the beam with the end face of the optical fiber and complete the focusing. At this time, the output light source power is at its maximum and the coupling efficiency is at its maximum.

[0135] This embodiment utilizes the spatial characteristics of an ellipsoid to determine the positional relationships of the device components and designs an automatically adjustable light source coupling device.

[0136] This embodiment decouples the light angle from the position of the light spot, clarifies the detailed adjustment process and calculation method, and greatly improves the coupling efficiency compared with traditional manual adjustment.

[0137] Example 2

[0138] The purpose of this embodiment is to provide an automatic adjustment method for light source coupling, wherein the optical center of the first reflecting mirror is located at one focus of the ellipsoid, the optical center of the adjustable focusing objective lens is located at another focus of the ellipsoid, and the plane containing the second reflecting mirror is tangent to the ellipsoidal surface, including:

[0139] The initial position range of the second reflector is determined based on the range of the incident angle of the beam incident on the first reflector.

[0140] Based on the initial position range of the second reflector, the position of the second reflector is moved. Based on the fiber coupling power of the light beam after passing through the first reflector, the second reflector and the adjustable focus objective lens into the fiber, the rotation angle of the first reflector and the second reflector is adjusted to change the incident position of the light spot on the fiber end face until the fiber coupling power is maximized.

[0141] Then, the first and second reflectors are controlled to rotate in the same direction and at the same angle to ensure that the incident angle of the beam into the adjustable focus objective remains unchanged, thereby changing the incident position of the beam on the adjustable focus objective and adjusting the incident direction of the beam into the center of the optical fiber until the optical fiber coupling power is maximized and the beam is incident along the optical fiber axis.

[0142] Adjust the focal length of the adjustable lens to align the beam with the fiber end face and complete the focusing.

[0143] In further embodiments, the following is also provided:

[0144] An electronic device includes a memory and a processor, as well as computer instructions stored in the memory and running on the processor. When executed by the processor, the computer instructions perform the method described in Embodiment 1. For brevity, further details are omitted here.

[0145] It should be understood that in this embodiment, the processor can be a central processing unit (CPU), or it can be other general-purpose processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), programmable gate arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. The general-purpose processor can be a microprocessor or any conventional processor, etc.

[0146] Memory may include read-only memory and random access memory, and provides instructions and data to the processor. A portion of memory may also include non-volatile random access memory. For example, memory may also store information about the device type.

[0147] A computer-readable storage medium for storing computer instructions, which, when executed by a processor, perform the method described in Embodiment 1.

[0148] The method in Embodiment 1 can be directly implemented by a hardware processor, or implemented by a combination of hardware and software modules within the processor. The software modules can reside in readily available storage media in the art, such as random access memory, flash memory, read-only memory, programmable read-only memory, electrically erasable programmable memory, or registers. This storage medium is located in memory; the processor reads information from the memory and, in conjunction with its hardware, completes the steps of the above method. To avoid repetition, a detailed description is not provided here.

[0149] A computer program product includes a computer program that, when executed by a processor, implements the method described in Embodiment 1.

[0150] The present invention also provides at least one computer program product tangibly stored on a non-transitory computer-readable storage medium. The computer program product includes computer-executable instructions, such as instructions included in program modules, which execute in a device on a target real or virtual processor to perform the processes / methods described above. Typically, program modules include routines, programs, libraries, objects, classes, components, data structures, etc., that perform specific tasks or implement specific abstract data types. In various embodiments, the functionality of program modules can be combined or divided among program modules as needed. The machine-executable instructions for the program modules can execute within a local or distributed device. In a distributed device, the program modules can reside in both local and remote storage media.

[0151] The computer program code used to implement the methods of the present invention may be written in one or more programming languages. This computer program code may be provided to a processor of a general-purpose computer, a special-purpose computer, or other programmable data processing device, such that when executed by the computer or other programmable data processing device, the program code causes the functions / operations specified in the flowcharts and / or block diagrams to be implemented. The program code may be executed entirely on a computer, partially on a computer, as a stand-alone software package, partially on a computer and partially on a remote computer, or entirely on a remote computer or server.

[0152] In the context of this invention, computer program code or related data may be carried by any suitable carrier to enable a device, apparatus, or processor to perform the various processes and operations described above. Examples of carriers include signals, computer-readable media, and the like. Examples of signals may include electrical, optical, radio, sound, or other forms of propagation signals, such as carrier waves, infrared signals, etc.

[0153] Those skilled in the art will recognize that the units and algorithm steps described in conjunction with the embodiments herein can be implemented in electronic hardware or a combination of computer software and electronic hardware. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of this application.

[0154] While the specific embodiments of the present invention have been described above in conjunction with the accompanying drawings, this is not intended to limit the scope of protection of the present invention. Those skilled in the art should understand that various modifications or variations that can be made by those skilled in the art without creative effort based on the technical solutions of the present invention are still within the scope of protection of the present invention.

Claims

1. An automatic adjustment device for light source coupling, characterized in that, include: Adjustable focusing objective lens, first reflecting mirror, second reflecting mirror, power detection module, focusing platform and control terminal; The optical center of the first reflecting mirror is located at one focus of the ellipsoid, and the optical center of the adjustable focusing objective lens is located at the other focus of the ellipsoid. The control terminal is used to move the position of the second reflector based on the initial position range of the second reflector, and adjust the rotation angle of the first and second reflectors based on the optical fiber coupled power of the light beam after it enters the optical fiber through the first reflector, the second reflector and the adjustable focus objective lens, as fed back by the power detection module, so as to change the incident position of the light spot on the end face of the optical fiber until the optical fiber coupled power is maximized. Then, the first and second reflectors are controlled to rotate in the same direction and at the same angle to ensure that the incident angle of the beam into the adjustable focus objective remains unchanged, thereby changing the incident position of the beam on the adjustable focus objective and adjusting the incident direction of the beam into the center of the optical fiber until the optical fiber coupling power is maximized and the beam is incident along the optical fiber axis. The focusing platform is used to adjust the focal length of the adjustable objective lens so that the beam is aligned with the fiber end face to complete focusing.

2. The automatic adjustment device for light source coupling as described in claim 1, characterized in that, The initial position range of the second reflecting mirror is determined as follows: The incident angle range of the beam incident on the first reflecting mirror is determined based on the diameter of the fiber end face and the distance from the adjustable focusing objective to the fiber end face. Based on the positions of the first reflecting mirror and the adjustable focusing objective, and by allowing the light beam to sequentially pass through the first reflecting mirror, the second reflecting mirror, and the adjustable focusing objective before entering the optical fiber, the initial position range of the second reflecting mirror is determined.

3. The automatic adjustment device for light source coupling as described in claim 2, characterized in that, Based on the position of the optical center of the second reflecting mirror on the ellipsoid and the position of the optical center of the adjustable focusing objective, the direction of the light beam incident on the adjustable focusing objective is determined. Combined with the angle between the light beam incident on the adjustable focusing objective and the optical axis, the initial position range of the second reflecting mirror is determined.

4. The automatic adjustment device for light source coupling as described in claim 1, characterized in that, Set the initial normal vector of the plane where the first reflecting mirror is located and the optical center position of the second reflecting mirror. Calculate the outgoing direction vector and the incoming direction vector based on the incident line of the first reflecting mirror and the outgoing line reflected by the second reflecting mirror to the adjustable objective lens. Based on the difference between the outgoing and incoming directions, obtain the unit normal vector of the first reflecting mirror that satisfies the law of reflection. Using the initial normal vector of the plane containing the first reflector as a reference, the rotation angle of the first reflector is determined based on the unit normal vector of the plane containing the first reflector.

5. The automatic adjustment device for light source coupling as described in claim 1, characterized in that, Set the initial normal vector of the plane where the second mirror is located. Based on the fact that the normal vector of the plane where the second mirror is located is in the same direction as the gradient of the ellipsoid at the optical center point of the second mirror, calculate the unit normal vector of the plane where the second mirror is located based on the surface gradient. Determine the rotation angle of the second mirror based on the unit normal vector of the plane where the second mirror is located.

6. The automatic adjustment device for light source coupling as described in claim 5, characterized in that, The rotation angle of the second reflecting mirror is determined based on the unit normal vector of the plane containing the second reflecting mirror, specifically as follows: Based on the components of the unit normal vector of the plane where the second mirror is located, the rotation angles corresponding to the two rotations around different coordinate axes can be obtained by inverse solution. The attitude of the second reflector is adjusted based on the rotation angle so that the normal vector of the plane containing the second reflector is consistent with the unit normal vector.

7. The automatic adjustment device for light source coupling as described in claim 1, characterized in that, According to the law of reflection of light, when the first and second reflecting mirrors rotate in the same direction and at the same angle, the angle between the incident direction and the outgoing direction of the light beam remains unchanged after it is reflected by the first and second reflecting mirrors.

8. The automatic adjustment device for light source coupling as described in claim 1, characterized in that, Based on the optical path length of the light beam between the first and second mirrors, the optimal exit angle of the second mirror, the angle between the normal to the plane containing the first mirror and the normal to the plane containing the second mirror, and the angle at which the first and second mirrors deflect in the same direction, the distance the light spot moves on the second mirror is calculated; based on the distance the light spot moves on the second mirror, the distance the light spot moves on the adjustable focusing objective lens is derived.

9. The automatic adjustment device for light source coupling as described in claim 8, characterized in that, Based on the distance the light spot moves on the second reflecting mirror, the distance the light spot moves on the adjustable focusing objective lens is derived using the sine theorem.

10. The automatic adjustment device for light source coupling as described in claim 1, characterized in that, The first and second reflectors are controlled according to a preset scanning trajectory on the fiber end face. A coarse scan is performed with a first moving step size, and the fiber coupling power fed back by the power detection module is recorded at each preset scanning position. The magnitude of the fiber coupling power corresponding to each preset scanning position is compared to determine the coarse adjustment position of the second reflector. With the coarse adjustment position of the second reflector as the center, the first and second reflectors are controlled to perform a fine scan on the fiber end face with a second moving step size. When the fiber coupling power fed back by the power detection module reaches its maximum value, the beam is aligned with the center of the fiber end face. The first moving step size is greater than the second moving step size.

11. The automatic adjustment device for light source coupling as described in claim 1, characterized in that, The first and second reflecting mirrors are controlled to perform a coarse scan on the adjustable focusing objective lens with a first displacement step size, and the fiber coupling power fed back by the power detection module is recorded at each landing point position. The magnitude of the fiber coupling power corresponding to each landing point position is compared to determine the coarse rotation angle combination of the first and second reflecting mirrors. With the coarse rotation angle combination of the first and second reflecting mirrors as the center, a fine scan is performed on the adjustable focusing objective lens with a second displacement step size. When the fiber coupling power fed back by the power detection module reaches its maximum value, the beam is incident along the fiber axis. The first displacement step size is greater than the second displacement step size.

12. A method for automatic adjustment of light source coupling, employing an automatic adjustment device for light source coupling as described in any one of claims 1-11, characterized in that, The optical center of the first reflecting mirror is located at one focus of the ellipsoid, and the optical center of the adjustable objective lens is located at the other focus of the ellipsoid, including: The initial position range of the second reflector is determined based on the range of the incident angle of the beam incident on the first reflector. Based on the initial position range of the second reflector, the position of the second reflector is moved. Based on the fiber coupling power of the light beam after passing through the first reflector, the second reflector and the adjustable focus objective lens into the fiber, the rotation angle of the first reflector and the second reflector is adjusted to change the incident position of the light spot on the fiber end face until the fiber coupling power is maximized. Then, the first and second reflectors are controlled to rotate in the same direction and at the same angle to ensure that the incident angle of the beam into the adjustable focus objective remains unchanged, thereby changing the incident position of the beam on the adjustable focus objective and adjusting the incident direction of the beam into the center of the optical fiber until the optical fiber coupling power is maximized and the beam is incident along the optical fiber axis. Adjust the focal length of the adjustable lens to align the beam with the fiber end face and complete the focusing.

13. An electronic device, characterized in that, It includes a memory and a processor, as well as computer instructions stored in the memory and running on the processor, which, when executed by the processor, perform the method of claim 12.

14. A computer-readable storage medium, characterized in that, Used to store computer instructions, which, when executed by a processor, perform the method of claim 12.

15. A computer program product, characterized in that, It includes a computer program that, when executed by a processor, implements the method of claim 12.

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