Point-contact high-stability low-deviation optical fiber collimator

Abstract

The utility model discloses a kind of point contact type high stability low excursion optical fiber collimator, it is related to optical fiber collimator technical field, including collimator main body, optical fiber inlet, adjusting cap, adjusting spring, lens support, top ring and lens assembly. The position adjustment of lens assembly is realized by screwing adjusting cap;Adjusting spring and lens support, lens support and top ring, the contact position of top ring and adjusting cap forms point contact or line contact structure.This structure greatly reduces contact area, reduces friction and abrasion, significantly improves the adjustment accuracy and stability of optical fiber collimator.In the adjustment process, optical beam excursion is greatly reduced, effectively solve the problem of optical beam excursion and jump that traditional optical fiber collimator appears when adjusting focal length.In addition, the design also simplifies processing technology, reduces production cost, improves the reliability and service life of product, applicable to high-precision optical communication and optical measurement etc.

Description

Technical Field

[0001] This utility model relates to the field of fiber optic collimator technology, and more specifically to a point-contact type high-stability, low-offset fiber optic collimator. Background Technology

[0002] A fiber optic collimator is a device used to couple laser light from free space into an optical fiber, or to output laser light from an optical fiber as an adjustable collimated beam for transmission to the outside.

[0003] A free-space fiber collimator is an optical device used to construct a spatial optical path, converting a diverging beam emitted from an optical fiber into a parallel beam. It is widely used in optical communication, laser processing, laser measurement, and optical laboratories. In these applications, the performance of the fiber collimator directly affects the efficiency and accuracy of optical signal transmission. Typically, based on the fiber's NA (nanoscale range), core mode field diameter, and the wavelength of the transmitted light, different focal length lenses are selected to output collimated light of the desired spot size. Collimated light refers to laser spot size that remains approximately constant over long distances; this is the most widespread application. In addition, users can adjust the distance between the lens and the fiber core to achieve laser beam contraction and expansion, placing the beam waist at different distances to fulfill specific optical requirements.

[0004] Fiber optic collimators operate on the principle of refraction through optical lenses. By adjusting the position of the lenses, the divergence angle or collimation state of the emitted beam can be changed to meet the needs of different applications. Their main performance indicators include the collimation (divergence angle) of the emitted beam, insertion loss, and optical alignment accuracy. These indicators directly affect the quality of optical signal transmission. In high-precision applications, fiber optic collimators with low insertion loss and high collimation are particularly needed to ensure signal integrity and accuracy.

[0005] Fiber optic collimators are crucial components connecting optical fibers to other optical elements, such as lasers and detectors. Their primary task is to introduce optical signals from external systems into the fiber. During this process, the fiber optic collimator needs excellent alignment capabilities and low-loss transmission characteristics. Therefore, the fiber optic collimator requires adjustable focal length, as the divergence characteristics of laser light input in free space are unknown; thus, adjusting the coupler's focal length is necessary to improve coupling efficiency. Coupling efficiency and alignment accuracy are important indicators for evaluating the performance of fiber optic collimators. High-quality couplers ensure minimal light loss while guaranteeing signal stability and interference resistance. Modern fiber optic collimators continuously innovate in material selection, processing technology, and structural design to adapt to the increasingly complex demands of optical communication applications. Since fiber optic collimators and optical fiber collimators each play a key role in the optical system, their performance directly affects the efficiency and reliability of the entire optical path system. Especially in optical communication, accurate collimation and efficient coupling are fundamental to achieving high-quality signal transmission.

[0006] Currently available rotary adjustable focus fiber collimator devices all have an unresolved technical challenge: during the process of adjusting the front and rear focal lengths, the emitted laser inevitably deviates from the ideal transmission direction (central axis of symmetry). This problem is caused by multiple factors, including gaps in the track design, the flatness of the contact surface, the matching of the main body and lens device, and the contact of the lens pushing device. Utility Model Content

[0007] In view of this, the present invention provides a point-contact type high-stability, low-offset fiber collimator, which aims to solve the above-mentioned technical problems.

[0008] To achieve the above objectives, the present invention adopts the following technical solution:

[0009] A point-contact type high-stability, low-offset fiber collimator includes: a collimator body, one end of which has a fiber optic inlet, and the other end of which is threadedly connected to an adjustment cap. An adjustment spring, a lens holder, and a top ring are sequentially arranged in the inner cavity of the collimator body from the fiber optic inlet toward the adjustment cap, abutting against each other. A lens assembly is provided inside the lens holder. The position of the lens assembly can be adjusted by turning the adjustment cap.

[0010] The contact positions of the adjusting spring and the lens holder, and / or the contact positions of the lens holder and the top ring, and / or the contact positions of the top ring and the adjusting cap form a point contact structure and / or a line contact structure.

[0011] Through the above technical solution, this utility model effectively reduces the contact area, reduces friction and wear, improves the adjustment accuracy and stability of the fiber optic collimator, reduces beam deviation during adjustment, enhances the long-term stability and service life of the fiber optic collimator by forming point contact structures and / or line contact structures at the contact positions of the adjusting spring and lens holder, the lens holder and top ring, and the top ring and adjusting cap. At the same time, it simplifies the processing technology and reduces production costs.

[0012] Preferably, in the above-mentioned point-contact high-stability low-offset fiber collimator, the end face of the lens holder that contacts the adjusting spring has a first protrusion, and the first protrusion abuts against the adjusting spring to form a point-contact structure or a line-contact structure.

[0013] Preferably, in the above-mentioned point-contact type high-stability low-offset fiber collimator, the first protrusion is softly connected to the adjusting spring.

[0014] Preferably, in the above-mentioned point-contact high-stability low-offset fiber collimator, at the contact position between the lens holder and the top ring, the end face of the lens holder or the top ring has a second protrusion, and the lens holder and the top ring abut against each other through the second protrusion to form a point-contact structure or a line-contact structure.

[0015] Preferably, in the above-mentioned point-contact high-stability low-offset fiber collimator, at the contact position between the top ring and the adjustment cap, the abutting surface of the adjustment cap is provided with an annular groove, so that the abutting surface of the adjustment cap forms a third convexity, and the third convexity abuts against the top ring to form a point contact structure or a line contact structure.

[0016] Preferably, in the above-mentioned point-contact type high-stability low-offset fiber collimator, there is an axial guide portion between the mating surfaces of the outer sidewall of the top ring and the inner sidewall of the collimator body. The axial guide portion is composed of an axial sliding fit structure of an axial protrusion and an axial groove, so that when the adjusting cap pushes the top ring to move, the top ring can only slide along the axial direction of the collimator body and is restricted from radial movement and circumferential rotation.

[0017] Preferably, in the above-mentioned point-contact type high-stability low-offset fiber collimator, either end of the lens holder is set as an inclined surface, so that the lens holder and the adjusting spring or the top ring form a ramp-type mating structure. Due to the inclined surface of the lens holder, the adjusting spring or the top ring at either end of the lens holder forms an oblique force relative to the lens holder that deviates from the axis of the collimator body, thereby causing an outer side wall of the lens holder to be pressed against the inner side wall of the collimator body.

[0018] Preferably, in the above-mentioned point-contact high-stability low-offset fiber collimator, when the end of the lens holder facing the top ring is inclined, the end face of the top ring is an inclined surface that matches the slope of the inclined surface of the lens holder.

[0019] Preferably, in the above-mentioned point-contact high-stability low-offset fiber collimator, the two ends of the lens holder are set as symmetrical inclined surfaces.

[0020] Preferably, in the above-mentioned point-contact high-stability low-offset fiber collimator, the collimator body is provided with a locking assembly for locking the lens holder. The locking assembly includes a set screw that is threadedly connected to the side wall of the collimator body, and a V-shaped groove corresponding to the set screw is axially opened on the outer side wall of the lens holder.

[0021] As can be seen from the above technical solution, compared with the prior art, this utility model discloses a point-contact type high-stability low-offset fiber collimator. Through a series of innovative designs, such as point-contact or line-contact structures, ramp-type mating structures, axial guides, and locking components, the adjustment accuracy and stability of the fiber collimator are significantly improved. It effectively reduces beam offset and jump phenomena during adjustment, reduces friction and wear, extends service life, simplifies the processing technology, reduces production costs, and improves the overall performance and reliability of the product, meeting the needs of high-precision optical communication and optical applications. Attached Figure Description

[0022] To more clearly illustrate the technical solutions in the embodiments of this utility model 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 embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0023] Figure 1 The attached figure is a cross-sectional view of an existing fiber optic collimator;

[0024] Figure 2 The attached diagram is an exploded view of an existing fiber optic collimator.

[0025] Figure 3 The attached figure is a cross-sectional view of the point-contact type high-stability low-offset fiber collimator of Embodiment 1 provided by this utility model.

[0026] Figure 4 The attached figure is a cross-sectional view of the point-contact type high-stability, low-offset fiber collimator of Embodiment 1 provided by this utility model;

[0027] Figure 5The attached figure is a cross-sectional view of the point-contact type high-stability, low-offset fiber collimator of Embodiment 2 provided by this utility model;

[0028] Figure 6 The attached figure is a cross-sectional view of the point-contact type high-stability, low-offset fiber collimator of Embodiment 3 provided by this utility model;

[0029] Figure 7 The attached figure is a cross-sectional view of the point-contact type high-stability, low-offset fiber collimator of Embodiment 4 provided by this utility model.

[0030] Figure 8 The attached figure is a cross-sectional view of the locking component provided by this utility model;

[0031] Figure 9 The attached figure is a radial cross-sectional view of the fiber optic collimator provided by this utility model;

[0032] Figure 10 The attached figure is a test schematic diagram of Embodiment 1 provided by this utility model.

[0033] in:

[0034] 1-Collider body;

[0035] 11-Fiber optic access point;

[0036] 2-Adjusting cap;

[0037] 21-Annular groove; 22-Third convex part;

[0038] 3-Adjusting spring;

[0039] 4-Lens holder;

[0040] 41 - First protrusion; 42 - Second protrusion; 43 - V-groove;

[0041] 5-Top ring;

[0042] 6-Axial guide section;

[0043] 61-Axial convex rib; 62-Axial groove;

[0044] 7-Sloping type mating structure;

[0045] 8- Locking component;

[0046] 81-Top screw. Detailed Implementation

[0047] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0048] The structure of a traditional fiber optic collimator is as follows: Figure 1 and Figure 2 As shown, it includes: a collimator body 1, one end of which has an optical fiber inlet 11, and the other end of which is threadedly connected to an adjustment cap 2. The inner cavity of the collimator body 1 is provided with an adjustment spring 3, a lens support 4 and a top ring 5 that abut against each other in sequence from the optical fiber inlet 11 toward the adjustment cap 2. The lens support 4 is provided with a lens assembly. The position of the lens assembly can be adjusted by turning the adjustment cap 2.

[0049] When adjusting the focus, two significant problems are often encountered: First, there is obvious resistance and friction during the rotation process, which not only affects the user experience, but also causes the long-term stability of the device to decrease due to the stress generated by friction; Second, due to the imbalance or inaccuracy of the rotating structure, there will be slight left and right disturbances during the adjustment process, which will cause the output beam to deflect and negatively affect the accurate transmission of the light signal.

[0050] like Figure 1 As shown, when adjusting the front and rear focal lengths by rotating the adjusting cap 2, the lens assembly undergoes undesirable rotation. When the adjusting cap 2 rotates, friction exists between it and the top ring 5, causing the top ring 5 to rotate with the adjusting cap 2. Friction also exists between the top ring 5 and the lens support 4, ultimately causing the lens assembly to rotate as well. This is undesirable, affecting the alignment stability of the collimator. Ideally, after light exits the fiber, the collimated laser should exit through the fiber optic connector 11, the lens assembly, and the central axis of other components. However, considering that the components are not necessarily perfectly centrosymmetric in principle, and that there will be some gaps in the tracks, this rotation will cause undesirable optical path off-axis, resulting in changes in the emitted and incident laser beams.

[0051] During the process of adjusting the focus by rotating the adjusting cap 2, uneven force transmission causes the lens to deviate from the originally set ideal central axis of symmetry. Specifically, the adjusting cap 2 is connected to the collimator body 1 by a thread, and there must be a necessary gap in between. This allows the direction of rotation of the adjusting cap 2 to deviate from the central axis of symmetry. A necessary gap is also required between the top ring 5 and the lens holder 4 and the collimator body 1; otherwise, they cannot slide. Therefore, any collimator with adjustable focus will have the potential for the emitted light to deviate from the collimated optical axis.

[0052] In other commercially available products, the contact surfaces of the adjusting cap 2 pushing the top ring 5 and the top ring pushing the lens holder 4 are both smooth planes. In actual operation, when rotating the adjusting cap 2 to move the top ring 5 and lens holder 4 back and forth, both contact surfaces are in full-surface contact, resulting in sliding friction. Considering the flatness and precision of the machined surfaces, when the two contact surfaces undergo both rotation and forward / backward movement, even the slightest unevenness in particle size will immediately generate non-uniform forces, leading to rotational deviation. Furthermore, considering the nature of the thread and the clearance space, there will always be non-centrally symmetrical left-right components of force during the pushing process. Therefore, the force transmitted by the adjusting cap 2 will change the orientation of the top ring 5, which will further be transmitted to the lens holder 4, causing the lens assembly to deviate from its central axis of symmetry. This problem will also cause the laser emission to deviate from the desired central axis of symmetry, which is undesirable during use.

[0053] Example 1:

[0054] See appendix Figure 3 and attached Figure 4 This utility model discloses a point-contact type high-stability low-offset fiber collimator, including: a collimator body 1, one end of the collimator body 1 has a fiber optic inlet 11, and the other end of the collimator body 1 is threadedly connected to an adjustment cap 2. The inner cavity of the collimator body 1 is provided with an adjustment spring 3, a lens support 4 and a top ring 5 that abut against each other in sequence from the fiber optic inlet 11 to the adjustment cap 2. The lens support 4 is provided with a lens assembly. The position of the lens assembly can be adjusted by turning the adjustment cap 2.

[0055] The contact position between the adjusting spring 3 and the lens holder 4, and / or the contact position between the lens holder 4 and the top ring 5, and / or the contact position between the top ring 5 and the adjusting cap 2, form a point contact structure and / or a line contact structure.

[0056] To further optimize the above technical solution, the end face of the lens holder 4 that contacts the adjusting spring 3 has a first protrusion 41, which abuts against the adjusting spring 3 to form a point contact structure or a line contact structure.

[0057] To further optimize the above technical solution, the first protrusion 41 is softly connected to the adjusting spring 3.

[0058] To further optimize the above technical solution, at the contact position between the lens holder 4 and the top ring 5, the end face of the lens holder 4 or the top ring 5 has a second protrusion 42, and the lens holder 4 and the top ring 5 abut against each other through the second protrusion 42 to form a point contact structure or a line contact structure.

[0059] To further optimize the above technical solution, at the contact position between the top ring 5 and the adjusting cap 2, an annular groove 21 is provided on the contact surface of the adjusting cap 2, so that the contact surface of the adjusting cap 2 forms a third protrusion 22, which abuts against the top ring 5 to form a point contact structure or a line contact structure.

[0060] To address the existing problems, this embodiment innovatively introduces a point contact structure or a line contact structure. Taking the second contact surface of the top ring 5 as an example, a very small arc-shaped protrusion is set on the contact surface to solve this problem. Furthermore, the contact area between the adjusting cap 2 and the top ring 5 is made into a hemispherical shape.

[0061] In this embodiment, the top ring 5 has a semi-cylindrical protrusion, forming a second protrusion 42, so that the part that contacts the lens holder 4 is a short line or a small surface. If the size can be processed very small, it can even be regarded as an ideal point contact. At this time, assuming it is a short line-shaped contact surface, the direction of this short line is defined as y, and the perpendicular direction is defined as x. The plane containing xy is the radial tangent of the collimator body 1, and z is the axial direction, that is, the direction of the lens moving back and forth. When the lens holder 4 is disturbed in the x direction, its force point is still at the position of the short line, and the elastic force direction is parallel to the z axis, that is, the elastic force direction does not change. If the disturbance occurs in the y direction, since it is a short line, the contact surface can be approximated as a point, and the elastic force direction is also parallel to the z axis. This design can significantly reduce the interference caused by the disturbance of the adjusting cap 2. It should be noted that this design can only have one point of contact with the lens holder 4 in the y direction (theoretically). If there are two, or if the contact area is too large, the disturbance will be transmitted and the most ideal effect cannot be achieved.

[0062] In addition, another significant advantage is that this embodiment proposes changing the connection method between the rotating structure and the collimator body 1 from traditional surface contact to point contact. This change significantly reduces the contact area, thereby reducing wear and friction. The point contact design not only reduces frictional resistance during rotation but also optimizes the friction type, transforming the friction between the adjusting spring 3, lens support 4, and top ring 5 into static friction, thus achieving a smoother rotation experience. Overall, in use, when adjusting the focus by rotating the adjustment knob, the blunting effect caused by friction is significantly reduced, and the entire process is very smooth.

[0063] It should be noted that the protrusion described in this embodiment is a smooth protrusion, achieving a small semi-cylindrical shape (the contact surface is a short line). Theoretically, a hemispherical protrusion would be best, representing point contact. Considering ease of manufacturing, a semi-cylindrical shape was chosen. It can be considered that a semi-cylindrical shape (small line contact) is approximately equal to a hemisphere (point contact). This solution is a compromise that combines ease of manufacturing and is not limited to a semi-circle or a specific arc shape. As long as it is a small protrusion serving as point contact, it is acceptable; a small square shape is also acceptable.

[0064] In addition to optimizing such issues by adding point contact structures to the contact surface, this embodiment can further optimize related performance by hollowing out a specially designed annular groove 21 inside the adjusting cap 2. The specific groove design makes the contact position between the adjusting cap 2 and the top ring 5 closer to the central axis and reduces the contact area. Its advantages are: (1) the contact at the front end changes from surface contact to line contact, which can reduce the offset when the adjusting cap 2 is offset; (2) the hollowing design can further reduce the weight of the adjusting cap 2, which not only reduces the overall weight to achieve optimization, but also reduces the weight ratio of the adjusting cap 2 separately, which can avoid the excessively heavy adjusting cap compressing the thread gap and causing a slight offset when moving the thread.

[0065] By applying the aforementioned innovations, the adjustable-focus collimator has undergone significant optimization in both principle and performance. Furthermore, in terms of machining, this invention reduces the stringent requirements for surface flatness through a point-contact design, simplifying the production process. This also reduces product quality issues caused by insufficient machining precision, improving manufacturing efficiency and yield. For the original collimator, because all contact surfaces were in full contact, the machining precision of the entire large plane was extremely high; insufficient machining precision significantly impacted performance. However, with the point-contact type, only the machining points need to be free of large depressions, maintaining a basic circular arc structure to achieve the desired principle optimization. This greatly reduces the precision requirements for machining, improves the yield rate, and thus lowers costs.

[0066] Example 2:

[0067] See appendix Figure 5 One end of the lens holder 4 is set as an inclined surface, so that the lens holder 4 and the adjusting spring 3 or the top ring 5 form a ramp-type mating structure 7. Through the inclined surface of the lens holder 4, the adjusting spring 3 or the top ring 5 at one end of the lens holder 4 forms an oblique force relative to the lens holder 4 that deviates from the axis of the collimator body 1, thereby causing one outer wall of the lens holder 4 to be pressed against the inner wall of the collimator body 1.

[0068] In this embodiment, there are several possible scenarios:

[0069] The lens holder 4 has an inclined surface facing the adjusting spring 3, forming a ramp-type mating structure 7 between the lens holder 4 and the adjusting spring 3. Because it is an inclined surface, the elastic force of the contact surface between the lens holder 4, the adjusting spring 3, and the top ring 5 is always inclined downwards, and the lens holder 4 is always in contact with the side wall of the collimator body 1. Simply put, when stationary and in motion, the two sides of the lens holder 4 are pressed against the inner wall of the collimator body 1 by the spring 3 and the top ring 5, respectively. This ensures that the axial component of the force is coaxial and avoids directional deviation caused by uneven force on the lens holder 4.

[0070] See appendix Figure 7 and attached Figure 9 The collimator body 1 is provided with a locking assembly 8 for locking the lens holder 4. The locking assembly 8 is opposite to the contact position of the lens holder 4 and the collimator body 1. The locking assembly 8 includes a set screw 81 that is threadedly connected to the side wall of the collimator body 1. A V-shaped groove 43 corresponding to the set screw 81 is axially opened on the outer side wall of the lens holder 4.

[0071] It should be noted that the V-groove 43 in this embodiment is designed to further improve stability. The V-groove 43 can also be designed independently without requiring the end face of the lens support 4 to be beveled, achieving the same effect of the lens support 4 always contacting the side wall of the collimator body 1. Here, the cooperation between the V-groove 43 and the set screw 81 serves two purposes: first, a limiting function during adjustment; and second, a locking function after adjustment.

[0072] In summary, this ensures that there will be no abrupt changes in the x and y directions when the lens holder 4 moves back and forth. Furthermore, when the locking component 8 is locked, the direction of the light does not change. The resultant force of the locking component 8 is in the same direction as the offset direction of the lens holder 4, thus restricting the position of the lens holder 4 and preventing abrupt changes when locked.

[0073] The inclination angle of the inclined plane is defined as θ, which is generally 3-25°. The radial component of the force will cause sliding friction on the contact surface between the lens support 4 and the collimator body 1. The larger the angle, the greater the friction. Therefore, the angle should not be too large, otherwise the spring force will not be able to push the lens support 4 to move, or the friction will be too large during use or when the focal length changes.

[0074] This method decouples the disturbance and avoids the abrupt changes during switching. It also prevents movement when locked, ensuring that the light spot direction remains unchanged in different adjustment states and when locked.

[0075] In this embodiment, the tilt angle of the inclined surface of the lens holder 4 is 5°.

[0076] To further optimize the above technical solution, the locking component 8 includes a set screw 81 that is threadedly connected to the side wall of the collimator body 1.

[0077] To further optimize the above technical solution, there are multiple set screws 81, which are arranged along the axial direction of the collimator body 1.

[0078] See appendix Figure 9 The outer wall of the lens holder 4 is provided with a V-shaped groove 43 corresponding to the set screw 81.

[0079] In this embodiment, set screw 81 is a wave screw.

[0080] The two sides of the top ball of the ball screw symmetrically abut against the two side walls of the V-groove 43.

[0081] In traditional collimators, during the locking process, due to the aforementioned instability factors, the direction of the resultant force on the lens support 4 when it is adjusted to the appropriate position is not the same as the direction of the elastic force of the locking clamp. Therefore, the beam direction changes during locking. This phenomenon needs to be eliminated and is undesirable during use; it is called the jump phenomenon. Therefore, one of the optimization points of this embodiment is to eliminate the jump phenomenon.

[0082] like Figure 7 As shown, by adding a V-groove 43 to the lens holder 4, a fixed and locked state is achieved, thus preventing jumps when locked. The small ball at the top of the ball screw contacts the V-groove 43, obtaining a resultant force in the y-direction. This resultant force can limit the left and right movement of the lens holder 4, maintaining directional stability during locking. During forward and backward displacement, the V-groove 43 can restrict the trajectory in the xy-direction, allowing the lens holder to move along the direction of the V-groove. In summary, this solution can also maintain stability during both adjustment and locking.

[0083] Alternatively, in other configurations, the side of the lens holder 4 facing the top ring 5 is sloped, creating a ramp-type mating structure 6 between the lens holder 4 and the top ring 5. When the end of the lens holder 4 facing the top ring 5 is sloped, the end face of the top ring 5 is a slope that matches the slope of the lens holder 4.

[0084] Alternatively, in other configurations, both ends of the lens holder 4 are beveled, forming a ramp-type mating structure 6 with the adjusting spring 3 and the top ring 5. The end face of the top ring 5 is a ramp that matches the slope of the lens holder 4. The ramps on both sides of the lens holder 4 are symmetrically arranged.

[0085] The inclined surface design in this embodiment can still be combined with the point contact structure of Embodiment 1 to form, as shown in the figure. Figure 5 The combined structure shown.

[0086] Example 3:

[0087] See appendix Figure 6Based on the optimization of Embodiment 2, the two beveled surfaces on both sides of the lens holder 4 can be further simplified. Both ends of the lens holder 4 can be beveled and curved. In this way, the adjusting spring 3 and the lens holder 4 will have two points tangent to the vertex of the curve, and the top ring 5 and the lens holder 4 will also have two vertices tangent to it. This can reduce friction and prevent the lens holder 4 from being selected.

[0088] In the structure of this embodiment, the apex of the arc forms the first convex part 41 and the second convex part 42.

[0089] Example 4:

[0090] See appendix Figure 7 An axial guide portion 6 is provided between the mating surfaces of the outer side wall of the top ring 5 and the inner side wall of the collimator body 1. The axial guide portion 6 is composed of an axial sliding fit structure of an axial protrusion 61 and an axial groove 62, so that when the adjusting cap 2 pushes the top ring 5 to move, the top ring 5 can only slide along the axial direction of the collimator body 1 and is restricted from radial movement and circumferential rotation.

[0091] In this embodiment, the axial guide portion 7 includes an axial protrusion 61 disposed on the outer side wall of the top ring 5, and an axial groove 62 disposed on the inner side wall of the collimator body 1 and slidably connected to the axial protrusion 61.

[0092] In other embodiments, the positions of the axial protrusion 61 and the axial groove 62 can be interchanged. For example, the axial guide portion 6 includes an axial protrusion 61 provided on the inner side wall of the collimator body 1, and an axial groove 62 provided on the outer side wall of the top ring 5 and slidably connected to the axial protrusion 61.

[0093] In this embodiment, both the axial protrusion 61 and the axial groove 62 are cuboid structures. However, the shape is not actually limited to rectangles; any shape that matches during assembly is acceptable.

[0094] Example 5:

[0095] This embodiment experimentally verifies the scheme of Embodiment 1:

[0096] An aspherical lens with a focal length of 11mm was selected as the collimating lens and placed in the lens holder 4. Single-mode PC fiber was selected as the optical fiber, and the transmitted laser was a continuous laser of 780nm.

[0097] We designed a second protrusion 42 on the top ring 5. The inner diameter of the top ring 5 is 7.2mm and the outer diameter is 9.5mm. The outer diameter of the second protrusion 42 is 12.3mm. The point contact structure is located directly above and is a semi-cylinder with a radius of 0.5mm and a height of 1.15mm. Theoretically, the point contact is a line segment with a length of 1.15mm. In addition, the adjusting cap 2 is also hollowed out, with a groove 2.6mm wide and 0.5mm deep. The adjusting cap 2 and the top ring 5 have line contact.

[0098] Next, we tested the collimator's performance. During the testing process, we selected the collimators before and after the improvement as comparative references. The specific test optical path is as follows: Figure 10 As shown, the laser is first transmitted through an optical fiber. After the fiber is inserted into the collimator, the focal length is adjusted to produce a long-distance collimated beam. The change of the laser spot with length is shown in Table 1 below:

[0099] Table 1

[0100] Spot size / μm 1517*1513 1467*1472 1508*1504 1692*1697 1852*1849

[0101] The beam waist diameter is 1460μm.

[0102] This basically proves that the light spot is collimated at this time.

[0103] The collimator is then fixed in place, and the laser transmission path is determined. A beam spot display screen is placed on a plane perpendicular to the laser beam, displaying the beam spot's position using a two-dimensional coordinate system. Alternatively, a beam quality analyzer can be used; such optoelectronic devices can directly convert the optical signal into the beam spot position, eliminating the need for manual reading. At this point, the distance between the collimator and the beam spot display screen is controlled at 2 meters.

[0104] Next, rotate adjustment cap 2 to adjust the focal length back and forth. The focal length adjustment range is controlled within ±0.25mm. Position 0 represents the optimal collimation point, where the collimated light divergence angle is the smallest, and the light spot on the observation screen is the smallest. Record the center position of the light spot every half turn of the adjustment cap, starting from -0.25mm to +0.25mm, and then continuing from +0.25mm back to -0.25mm, recording the light spot trajectory of one round trip.

[0105] (1) During adjustment, the optimized collimator exhibited a maximum offset of 39 μm in the x-direction (vertical direction of the radial direction), corresponding to 0.0195 mrad, and a maximum offset of 160 μm in the y-direction (lateral direction of the radial direction), corresponding to 0.08 mrad. Furthermore, no significant jump occurred during switching between the two directions, as shown in Table 2.

[0106] Table 2

[0107] coordinates / μm (-10,158) (38,101) (0,0) (39,-83) (-34,10) (15,-65) (-5,112) (10,160) (-32,119)

[0108] (2) Before optimization, the collimator exhibited a maximum offset of 2537 μm in the x-direction (corresponding to 1.26 mrad) and a maximum offset of 1568 μm in the y-direction (corresponding to 0.78 mrad) during adjustment. Furthermore, there were significant jumps during the switching between the two directions, as shown in Table 3.

[0109] Table 3

[0110] coordinates / μm (-595,1008) (354,987) (0,0) (-735,-113) (419,1386) (-1698,-69) (-2537,-653) (-1484,-1568) (-756,-994)

[0111] The above-mentioned indicators are superior to similar products from other manufacturers and traditional collimators that have not been optimized. Therefore, with the addition of this optimized collimator, there will be no significant left-right shift caused by rotation during focus adjustment.

[0112] To optimize friction and lifespan, H65 copper material with a surface finish of ▽8 is used here.

[0113] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on its differences from other embodiments. Similar or identical parts between embodiments can be referred to interchangeably. For the apparatus disclosed in the embodiments, since it corresponds to the method disclosed in the embodiments, the description is relatively simple; relevant parts can be referred to the method section.

[0114] The above description of the disclosed embodiments enables those skilled in the art to make or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A point-contact type high-stability, low-offset fiber collimator, comprising: A collimator body (1) has an optical fiber inlet (11) at one end and an adjusting cap (2) threaded to the other end. The inner cavity of the collimator body (1) contains an adjusting spring (3), a lens holder (4), and a top ring (5) arranged sequentially from the optical fiber inlet (11) towards the adjusting cap (2). A lens assembly is housed within the lens holder (4), and the position of the lens assembly can be adjusted by turning the adjusting cap (2). The collimator body (1) is characterized by: The contact positions of the adjusting spring (3) and the lens holder (4), and / or the contact positions of the lens holder (4) and the top ring (5), and / or the contact positions of the top ring (5) and the adjusting cap (2) form a point contact structure and / or a line contact structure.

2. The point-contact type high-stability, low-offset fiber collimator according to claim 1, characterized in that, The end face of the lens holder (4) that contacts the adjusting spring (3) has a first protrusion (41), which abuts against the adjusting spring (3) to form a point contact structure or a line contact structure.

3. The point-contact type high-stability, low-offset fiber collimator according to claim 2, characterized in that, The first protrusion (41) is softly connected to the adjusting spring (3).

4. A point-contact type high-stability, low-offset fiber collimator according to any one of claims 1-3, characterized in that, At the contact position between the lens holder (4) and the top ring (5), the end face of the lens holder (4) or the top ring (5) has a second protrusion (42), and the lens holder (4) and the top ring (5) abut against each other through the second protrusion (42) to form a point contact structure or a line contact structure.

5. A point-contact type high-stability, low-offset fiber collimator according to claim 4, characterized in that, At the contact position between the top ring (5) and the adjusting cap (2), the abutting surface of the adjusting cap (2) is provided with an annular groove (21), so that the abutting surface of the adjusting cap (2) forms a third protrusion (22), and the third protrusion (22) abuts against the top ring (5) to form a point contact structure or a line contact structure.

6. A point-contact type high-stability, low-offset fiber collimator according to claim 1, characterized in that, The outer side wall of the top ring (5) and the inner side wall of the collimator body (1) have an axial guide portion (6). The axial guide portion (6) is composed of an axial sliding fit structure of an axial protrusion (61) and an axial groove (62), so that when the adjusting cap (2) pushes the top ring (5) to move, the top ring (5) can only slide along the axial direction of the collimator body (1) and is restricted from radial movement and circumferential rotation.

7. A point-contact type high-stability, low-offset fiber collimator according to claim 1, characterized in that, One end of the lens holder (4) is set as an inclined surface, so that the lens holder (4) and the adjusting spring (3) or the top ring (5) form a ramp-type mating structure (7). Through the inclined surface of the lens holder (4), the adjusting spring (3) or the top ring (5) at one end of the lens holder (4) forms an oblique force relative to the lens holder (4) that deviates from the axis of the collimator body (1), thereby causing one outer side wall of the lens holder (4) to be pressed against the inner side wall of the collimator body (1).

8. A point-contact type high-stability, low-offset fiber collimator according to claim 7, characterized in that, When the end of the lens holder (4) facing the top ring (5) is an inclined surface, the end face of the top ring (5) is an inclined surface that matches the slope of the lens holder (4).

9. A point-contact type high-stability, low-offset fiber collimator according to claim 7, characterized in that, The two ends of the lens holder (4) are designed as symmetrical inclined surfaces.

10. A point-contact type high-stability, low-offset fiber collimator according to any one of claims 1-9, characterized in that, The collimator body (1) is provided with a locking assembly (8) for locking the lens holder (4). The locking assembly (8) includes a set screw (81) that is threadedly connected to the side wall of the collimator body (1). A V-shaped groove (43) corresponding to the set screw (81) is axially opened on the outer side wall of the lens holder (4).

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