Device and method for testing eccentricity of optical fiber collimator

Abstract

The invention discloses an optical fiber collimator eccentricity testing device, which comprises a lens assembly, a first plane spectroscope, a second plane spectroscope and a scale plate, and is characterized in that an optical fiber collimator, the lens assembly, the first plane spectroscope, the second plane spectroscope and the scale plate are sequentially arranged; a light incident angle of a light beam emitted by the optical fiber collimator is amplified and the diameter of the light beam is compressed through the lens assembly, and then the light beam is split and reflected twice through the first plane spectroscope and the second plane spectroscope, so that the light beam reaches the scale plate along two different paths, and finally two light spots are formed on the scale plate. The distance between the two light spots on the scale plate is used for calculating the center deviation angle of the optical fiber collimator. According to the invention, the central deviation angle of the optical fiber collimator can be directly obtained by reading the distance between the two light spots on the scale plate, and angle measurement of grading precision is realized.

Description

Technical Field

[0001] The present invention relates to the technical field of optical measurement, and in particular to a device and method for testing the eccentricity of an optical fiber collimator. Background Art

[0002] Fiber optic collimator is one of the core optical components in the fields of fiber optic communication, laser technology, optical sensing, etc. Its core function is to achieve efficient coupling between optical fiber and free-space light (or optical components). The eccentricity of the fiber optic collimator has a significant impact on the coupling between optical components. Therefore, the detection of the center offset of the fiber optic collimator is particularly important.

[0003] Currently, the mainstream eccentricity measurement methods include interferometry and autocollimation imaging. Interferometry has high accuracy, but its environmental requirements are harsh, it is expensive, and the operation is complicated, making it difficult to perform large-scale and rapid measurements on fiber collimators. The autocollimation imaging method requires the fiber collimator to be rotated one circle to calculate the diameter of the circular trajectory of its image to obtain data. It has high requirements on the accuracy of the turntable, the measurement speed is slow, and it is not suitable for rapid measurement of fiber collimators. Summary of the Invention

[0004] To overcome the above-mentioned deficiencies of the prior art, the present invention provides a device and method for testing the eccentricity of a fiber collimator, which realizes the graded accuracy measurement of the center eccentricity angle of the fiber collimator by setting two parallel plane beam splitters.

[0005] According to one aspect of the present invention, a device for testing the eccentricity of a fiber collimator is provided. The device comprises a lens assembly, a first plane beam splitter, a second plane beam splitter, and a scale plate, wherein the fiber collimator, the lens assembly, the first plane beam splitter, the second plane beam splitter, and the scale plate are arranged in sequence. A light beam emitted by the fiber collimator passes through the lens assembly to amplify the incident angle of the light and compress the light diameter. The light beam then undergoes two splitting and reflections by the first plane beam splitter and the second plane beam splitter, so that the light beam reaches the scale plate along two different paths, and finally forms two light spots on the scale plate. The distance between the two light spots on the scale plate is used to calculate the center eccentricity angle of the fiber collimator.

[0006] Furthermore, the formula for calculating the center deviation angle of the fiber collimator based on the distance between the two light spots on the scale plate is α=arctan(d / 2L) / 6; wherein α represents the center deviation angle of the fiber collimator, d represents the distance between the two light spots on the scale plate, and L represents the distance between the first plane beam splitter and the second plane beam splitter.

[0007] Furthermore, the distance between the first plane beam splitter and the second plane beam splitter is designed to be 286.5 mm, and the center offset angle of the fiber collimator is equal to the distance between the two light spots on the scale plate.

[0008] Furthermore, the testing device also includes a translation stage and a collimator fixing fixture. The collimator fixing fixture is placed on the translation stage and is used to fix the optical fiber collimator. The translation stage is provided with rotation and pitch knobs to adjust the angle of the optical fiber collimator.

[0009] Furthermore, the lens assembly is a telescopic lens assembly, which includes a double-glued lens and a Huygens eyepiece, and the double-glued lens and the Huygens eyepiece are combined to compress the beam diameter of the incident light and magnify the incident angle of the incident light.

[0010] Furthermore, the telephoto lens assembly magnifies the incident angle of the incident light at an angular magnification of 1:6.

[0011] Furthermore, the testing device further includes a first spectroscope adjustment frame and a second spectroscope adjustment frame, wherein the first spectroscope adjustment frame and the second spectroscope adjustment frame are used to adjust the angles of the first plane spectroscope and the second plane spectroscope, respectively.

[0012] Furthermore, the first plane beam splitter and the second plane beam splitter are both 1 / 2 plane beam splitters.

[0013] According to one aspect of the present invention, a method for testing the eccentricity of a fiber collimator is provided, which is implemented using the fiber collimator eccentricity testing device. The method includes: calibrating the testing device using a standard fiber collimator; placing the fiber collimator to be tested on a collimator fixture; reading the distance between the center positions of two light spots on a scale plate, and calculating the center eccentricity angle of the fiber collimator based on the spacing between the two light spots on the scale plate.

[0014] Furthermore, the test device is calibrated using a standard fiber collimator, specifically including: placing the standard fiber collimator on a collimator fixture; observing the position of the bright light spot on the scale plate, and adjusting the translation stage so that the center of the light spot falls on the center scale; observing the two light spots on the first plane beam splitter, and adjusting the second beam splitter adjustment frame so that the two light spots coincide; observing the two light spots on the scale plate, and adjusting the first beam splitter adjustment frame so that the two light spots coincide at the center scale.

[0015] The above technical solution forms two light spots on the scale plate by passing the light emitted by the fiber collimator through two plane beam splitters, and calculates the center deviation angle of the fiber collimator according to the distance between the two light spots on the scale plate.

[0016] Compared with the prior art, the present invention has the following beneficial effects:

[0017] (1) The graded accuracy measurement of the center deviation angle of the fiber collimator is achieved by two parallel plane beam splitters, and the measurement data can be obtained without rotating the fiber collimator.

[0018] (2) The measurement steps are simple. The grading accuracy measurement results of the center deviation angle of the fiber collimator can be directly obtained by simply reading the distance between the two light spots on the scale plate.

[0019] (3) Calibration is easy, and only a standard fiber collimator is needed to complete the calibration without the help of other instruments. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 A schematic diagram of a test device for optical fiber collimator eccentricity provided in an embodiment of the present invention

[0021] Figure 2 A schematic diagram of the measurement principle of an optical fiber collimator eccentricity provided in an embodiment of the present invention

[0022] Figure 3 A schematic structural diagram of a scale plate provided in an embodiment of the present invention

[0023] Figure 4 Flow chart of a method for testing the eccentricity of a fiber collimator provided in an embodiment of the present invention

[0024] Figure 5 A sub-flow chart of a method for testing the eccentricity of a fiber collimator provided in an embodiment of the present invention

[0025] In the figure: 1. base; 2. translation stage; 3. collimator fixing fixture; 4. lens bracket; 5. lens assembly; 6. first beam splitter adjustment frame; 7. first plane beam splitter; 8. second beam splitter adjustment frame; 9. second plane beam splitter; 10. scale plate; 100. test device; 200. fiber collimator. DETAILED DESCRIPTION

[0026] The following will clearly and completely describe the technical solutions of various embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts are within the scope of protection of the present invention.

[0027] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise" and the like to indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0028] In the description of the present invention, it should be noted that, unless otherwise expressly specified or limited, the terms "mounted," "connected," and "connected" should be understood in a broad sense. For example, they may refer to fixed connections, detachable connections, or integral connections; mechanical connections, electrical connections, or mutual communication; direct connections or indirect connections through an intermediate medium; and internal communication between two components or interaction between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on specific circumstances.

[0029] In the present invention, unless otherwise expressly specified or limited, a first feature being "above" or "below" a second feature may include the first and second features being in direct contact, or may include the first and second features being in contact not directly but through another feature between them. Furthermore, a first feature being "above," "above," and "above" a second feature may include the first feature being directly above or obliquely above the second feature, or may simply mean that the first feature is higher in level than the second feature. A first feature being "below," "below," and "below" a second feature may include the first feature being directly below or obliquely below the second feature, or may simply mean that the first feature is lower in level than the second feature.

[0030] Please see attached Figure 1This embodiment provides a test device 100 for optical fiber collimator eccentricity. The test device 100 includes a base 1 and a displacement stage 2 and a collimator fixing fixture 3, a lens holder 4 and a lens assembly 5, a first beam splitter adjustment frame 6 and a first plane beam splitter 7, a second beam splitter adjustment frame 8 and a second plane beam splitter 9, and a scale plate 10, which are sequentially placed on the base 1. The collimator fixing fixture 3 is placed on the displacement stage 2. The collimator fixing fixture 3 is used to fix the optical fiber collimator 200. The displacement stage 2 is used to adjust the angle of the optical fiber collimator 200. The lens holder 4 is used to place the lens assembly 10. The first plane beam splitter 7 and the second plane beam splitter 9 are placed on the first beam splitter adjustment frame 6 and the second beam splitter adjustment frame 8, respectively, to adjust the angles of the first plane beam splitter 7 and the second plane beam splitter 9. The light beam emitted by the fiber collimator 200 passes through the lens assembly 5 to magnify the light incident angle and compress the light diameter. It then undergoes two splitting and reflections by the first plane beam splitter 7 and the second plane beam splitter 9, causing the light beam to reach the scale plate 10 along two different paths. Finally, two light spots are formed on the scale plate 10. The distance between the two light spots on the scale plate 10 is used by testers to calculate the center deviation angle of the fiber collimator 200.

[0031] In this embodiment, a V-groove is provided on the collimator fixture 3 to secure the fiber collimator 200, ensuring that the mechanical axis of the fiber collimator 200 aligns with the mechanical axis of the V-groove. The translation stage 2 is equipped with rotation and pitch knobs to adjust the angle of the collimator fixture 3, thereby aligning the mechanical axis of the V-groove with the optical axis of the lens assembly 5. This, in turn, aligns the mechanical axis of the fiber collimator 200, mounted on the collimator fixture 3, with the optical axis of the lens assembly 5.

[0032] Please refer to the attached Figure 2 In this embodiment, the lens holder 4 is a V-shaped telescopic lens holder, and the lens assembly 5 is a telescopic lens assembly 5. The telescopic lens assembly 5 includes a double-glued lens and a Huygens eyepiece. By combining the double-glued lens and the Huygens eyepiece, the beam diameter of the incident light is compressed and the incident angle of the incident light is magnified, thereby reducing aberrations and improving measurement accuracy. In this embodiment, the telescopic lens assembly 5 magnifies the incident angle of the incident light with an angular magnification ratio of 1:6. It can be understood that when the center deviation angle of the fiber collimator 200 is α, the incident light passes through the telescopic system with an angular magnification ratio of 1:6 to magnify the incident angle, the angle of the output light is 6α, and the output light diameter is 1 / 6 of the incident light.

[0033] It should be noted that the present invention passes the light emitted by the fiber collimator 200 through two plane beamsplitters to form two light spots on the scale plate 10. This allows the tester to calculate the center deviation angle of the fiber collimator 200 under test based on the spacing between the two light spots on the scale plate 10. In other words, the present invention converts "center deviation angle measurement" into "spot spacing measurement." Since the center deviation angle of the fiber collimator 200 is typically small, the spacing between the light spots projected on the scale plate 10 is also small. Directly measuring this tiny spot spacing requires extremely high-precision equipment. Therefore, before the light enters the plane beamsplitters, it is necessary to magnify the angle through the telescope lens assembly 5. This increases the spacing between the light spots on the scale plate 10, making it discernible to the naked eye or a low-precision ruler, significantly reducing the measurement difficulty. Furthermore, the beam diameter output by the fiber collimator 200 is typically large. The telescope lens assembly 5 reduces the beam diameter, resulting in a smaller spot on the scale plate 10. This reduces the edge blur caused by an overly large spot, thereby improving reading accuracy.

[0034] In this embodiment, the first beam splitter adjustment frame 6 and the second beam splitter adjustment frame 8 are each provided with three adjustment knobs, which can be used to adjust the angles of the first plane beam splitter 7 and the second plane beam splitter 9, thereby calibrating the first plane beam splitter 7 and the second plane beam splitter 9 to be perpendicular to the optical axis of the incident light. The first plane beam splitter 7 and the second plane beam splitter 9 are both 1 / 2 plane beam splitters. It can be understood that a plane beam splitter divides the incident light into transmitted light and reflected light. The "1 / 2" in the 1 / 2 plane beam splitter refers to the energy distribution ratio of the plane beam splitter to the transmitted light and the reflected light. That is, when a beam of light is perpendicularly incident on the surface of the 1 / 2 plane beam splitter, the 1 / 2 plane beam splitter will distribute the light intensity (energy) of the reflected light and the transmitted light to each account for 1 / 2 of the incident light.

[0035] Please refer to the attached Figure 2-3 The light emitted by the fiber collimator 200 passes through the first plane beam splitter 7 and is divided into transmitted light T1 and reflected light R1. The transmitted light T1 passes through the second plane beam splitter 9 and is divided into transmitted light T2 and reflected light R2. The transmitted light T2 hits the scale plate 10 to form the first light spot A. The reflected light R2 passes through the first plane beam splitter 7 again and is divided into transmitted light T3 and reflected light R3. The reflected light R3 passes through the second plane beam splitter 9 and is divided into reflected light R4 and transmitted light T4. The transmitted light T4 hits the scale plate 10 to form the second light spot B. It can be understood that because the light spots A and B correspond to different optical path lengths and the number of reflections of the light beams, the brightness of the two light spots is also different. The light spots A and B correspond to bright and dark spots, respectively.

[0036] Please refer to Figure 4The present invention also provides a method for testing the eccentricity of a fiber collimator, which uses the aforementioned testing device 100 to test the center eccentricity angle of the fiber collimator 200, comprising the following steps (steps S101-S105):

[0037] Step S101: calibrate the test device using a standard optical fiber collimator.

[0038] In step S101, before using the test device 100 to measure the center deviation angle of the fiber collimator 200, the test device 100 needs to be calibrated with a standard fiber collimator. Figure 5 , the process of calibrating the testing device 100 (including steps S1011 - S1015 ) will be further introduced below.

[0039] Step S1011: Place the standard fiber collimator on the collimator fixture. Specifically, first place the standard fiber collimator on the V-groove of the collimator fixture 3 and secure it. Observe whether the two light spots A and B on the scale plate 10 overlap at the center scale of the scale plate 10. If the two light spots A and B overlap at the center scale, it indicates that the test device 100 is normal and no calibration is required. The calibration process is exited. If the two light spots A and B do not overlap at the center scale, the test device 100 needs to be calibrated and step S1013 is executed.

[0040] In step S1013, observe the position of the bright spot on the scale plate and adjust the translation stage so that the center of the spot falls on the center scale. Specifically, first observe whether spot A (i.e., the bright spot) on scale plate 10 is at the center scale. If spot A is at the center scale, the angle of the V-groove of the collimator fixture 3 is normal. If spot A is not at the center scale, adjust the rotation and pitch knobs of translation stage 2 until spot A falls at the center scale. This indicates that the mechanical axis of the V-groove in the collimator fixture 3 is aligned with the optical axis of the lens assembly 5, and the calibration of the collimator fixture 3 is complete. Upon completion of the previous step, observe whether spots A and B on scale plate 10 overlap. If so, the angles of the first and second plane beam splitters 7 and 9 are normal, indicating that the entire test device 100 is calibrated, and the calibration process exits. If spots A and B do not overlap, proceed to step S1015.

[0041] In step S1015, the two light spots on the first plane beam splitter are observed, and the second beam splitter adjustment frame is adjusted to make the two light spots overlap. Specifically, the light spots A' and B' on the first plane beam splitter 7 are observed to see if they overlap. If they do, the angle of the second plane beam splitter 9 is normal. If they do not overlap, the second beam splitter adjustment frame 8 is adjusted to make the light spots A' and B' overlap. At this point, the second plane beam splitter 9 is perpendicular to the optical axis, and the calibration of the second plane beam splitter 9 is complete.

[0042] In step S1017, the two light spots on the scale plate are observed, and the first beam splitter adjustment frame is adjusted so that the two light spots overlap at the center scale. Specifically, the light spots A and B on the scale plate 10 are observed to see if they overlap. If they do, the angle of the first plane beam splitter 7 is normal, the entire test device 100 is calibrated, and the calibration process is exited. If the light spots A and B do not overlap, the first beam splitter adjustment frame 6 is adjusted so that the light spots A and B overlap. At this point, the first plane beam splitter 7 is perpendicular to the optical axis, the entire test device 100 is calibrated, and the calibration process is exited.

[0043] Step S103 : placing the optical fiber collimator to be tested on the collimator fixing fixture. Specifically, placing the optical fiber collimator to be tested 200 in the V-shaped groove of the collimator fixing fixture 3 .

[0044] In step S105, the distance between the centers of the two light spots on the scale plate is read, and the center deviation angle of the fiber collimator to be tested is calculated based on the spacing between the two light spots on the scale plate. Specifically, the scale plate 10 is marked with a scale, and the tester directly reads the spacing between the two light spots A and B on the scale plate 10. The center deviation angle of the fiber collimator 200 is calculated based on the spacing between the two light spots A and B on the scale plate 10. The formula is 6α=arctan(d / 2L), that is, α=arctan(d / 2L) / 6; where α represents the center deviation angle of the fiber collimator 200, d represents the spacing between the two light spots A and B on the scale plate 10, and L represents the spacing between the first plane beam splitter 7 and the second plane beam splitter 9. It should be noted that the parameter L can be optimized to make the center deviation angle α correspond to an integer multiple of the light spot spacing d, thereby facilitating the calculation of the center deviation angle α. Preferably, in this embodiment, L is set to 286.5 mm. In this case, the distance d between the two light spots read is the center deviation angle α, eliminating the need for trigonometric calculations. For example, if the distance d between the two light spots A and B on the scale plate 10 is 3 mm, the center deviation angle of the fiber collimator 200 can be directly deduced to be 3'. Therefore, the present invention achieves angle measurement with graded accuracy (1 degree = 60 minutes, or 1° = 60'), achieving an angle measurement accuracy of 1 minute).

[0045] In summary, the present invention utilizes two parallel plane beamsplitters to achieve graded accuracy measurement of the center deviation angle of a fiber collimator. This allows the center deviation angle of the fiber collimator to be calculated directly from the distance between the two light spots on the scale plate, without the need to rotate the fiber collimator. Furthermore, calibration of the test device can be completed with only a single standard fiber collimator, without the need for additional instruments.

[0046] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the technical solutions of the embodiments of the present invention.

Claims

1. A device for testing the eccentricity of a fiber collimator, characterized in that: The testing device includes a lens assembly, a first plane beam splitter, a second plane beam splitter, and a scale plate. The optical fiber collimator, lens assembly, first plane beam splitter, second plane beam splitter, and scale plate are placed in sequence. The light beam emitted by the optical fiber collimator passes through the lens assembly to amplify the light incident angle and compress the light diameter. The light beam then undergoes two splitting and reflections by the first plane beam splitter and the second plane beam splitter, so that the light beam reaches the scale plate along two different paths. Finally, two light spots are formed on the scale plate. The distance between the two light spots on the scale plate is used to calculate the center deviation angle of the optical fiber collimator.

2. A device for testing optical fiber collimator eccentricity according to claim 1, characterized in that: The formula for calculating the center deviation angle of the fiber collimator based on the distance between the two light spots on the scale plate is α=arctan(d / 2L) / 6; wherein α represents the center deviation angle of the fiber collimator, d represents the distance between the two light spots on the scale plate, and L represents the distance between the first plane beam splitter and the second plane beam splitter.

3. The optical fiber collimator eccentricity testing device according to claim 2, characterized in that: The distance between the first plane beam splitter and the second plane beam splitter is designed to be 286.5 mm, and the center deviation angle of the fiber collimator is equal to the distance between the two light spots on the scale plate.

4. The optical fiber collimator eccentricity testing device according to claim 1, characterized in that: The testing device also includes a translation stage and a collimator fixing fixture. The collimator fixing fixture is placed on the translation stage and is used to fix the optical fiber collimator. The translation stage is provided with rotation and pitch knobs to adjust the angle of the optical fiber collimator.

5. The optical fiber collimator eccentricity testing device according to claim 1, characterized in that: The lens assembly is a telescopic lens assembly, which includes a double-glued lens and a Huygens eyepiece. The double-glued lens and the Huygens eyepiece are combined to compress the beam diameter of the incident light and magnify the incident angle of the incident light.

6. The optical fiber collimator eccentricity testing device according to claim 5, characterized in that: The telephoto lens assembly magnifies the incident angle of incident light at an angular magnification of 1:

6.

7. The optical fiber collimator eccentricity testing device according to claim 1, characterized in that: The testing device further includes a first spectroscope adjustment frame and a second spectroscope adjustment frame, wherein the first spectroscope adjustment frame and the second spectroscope adjustment frame are used to adjust the angles of the first plane spectroscope and the second plane spectroscope respectively.

8. The optical fiber collimator eccentricity testing device according to claim 1, characterized in that: The first plane beam splitter and the second plane beam splitter are both 1 / 2 plane beam splitters.

9. A method for testing the eccentricity of a fiber collimator, characterized in that: The optical fiber collimator eccentricity test device according to any one of claims 1 to 8 is used for implementation, and the test method comprises: Calibrate the test device using a standard fiber collimator; Place the optical fiber collimator to be tested on the collimator fixing fixture; The distance between the center positions of the two light spots on the scale plate is read, and the center deviation angle of the optical fiber collimator to be tested is calculated according to the distance between the two light spots on the scale plate.

10. A method for testing eccentricity of a fiber collimator according to claim 9, characterized in that: The test device is calibrated using a standard fiber collimator, specifically including: Place the standard fiber collimator on the collimator fixture; Observe the position of the bright spot on the scale plate and adjust the translation stage so that the center of the spot falls on the center scale; Observe the two light spots on the first plane beam splitter and adjust the second beam splitter adjustment frame to make the two light spots overlap; Observe the two light spots on the scale plate and adjust the first beam splitter adjustment frame so that the two light spots overlap at the center scale.

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