Adjustable optical fiber delay line

Abstract

The utility model relates to the technical field of laser communication, and discloses an adjustable optical fiber delay line, which comprises an adjustable optical fiber delay line, a base, a prism slidably mounted on the base, an optical fiber input part, an optical fiber output part, a reflector slidably mounted on the base through an electric sliding table mechanism along the length direction of the adjustable optical fiber delay line, and an optical fiber output part slidably mounted on the base through an electric sliding table mechanism. The reflecting mirror is fixed on the base, the normal direction of the reflecting surface of the reflecting mirror is parallel to the length direction, the prism is a total reflection prism, the incident surface of the prism is perpendicular to the length direction, the incident light of the prism is parallel to but does not coincide with the emergent light corresponding to the incident light, and the laser coupler comprises a trunk optical fiber, a first branch optical fiber and a second branch optical fiber. According to the utility model, the electric sliding table drives the prism to slide, so that external laser is reflected through the prism, the shifting plate and the reflecting lens, the optical path distance is prolonged, and the effects of the same optical path difference adjusting range and the reduction of the prism sliding distance are achieved.

Description

Technical Field

[0001] This utility model relates to the field of laser communication technology, and in particular to an adjustable fiber delay line. Background Technology

[0002] Components or devices used to delay electrical signals for a period of time are called delay lines. In recent years, with the rapid development of the electronics industry, these components have been widely used in precision oscilloscopes, color televisions, electronic computers, industrial process control, modern radar systems, and other fields. Common types of delay lines include coaxial cable delay lines, ultrasonic delay lines, and fiber optic delay lines. In the quality inspection of fiber optic delay lines, polarization-dependent loss testing is required. The smaller the polarization-dependent loss value, the better the performance of the device.

[0003] When testing the polarization-dependent loss of tunable fiber delay lines, a laser polarization controller, such as a rotating polarizer, waveplate group, or paddle polarization controller, is usually required to simulate all polarization states of the laser so that the maximum and minimum transmission power of the tunable fiber delay line under all polarization states can be obtained by using an optical power meter.

[0004] Testing the polarization-dependent loss of tunable fiber delay lines typically requires an external laser polarization controller, optical power meter, tunable laser, and corresponding software. The external laser polarization controller's optical path connection increases the unreliability of the test. Existing tunable fiber delay lines only contain one round of optical path reflection, resulting in a narrow adjustable optical path difference range. Therefore, this tunable fiber delay line is proposed to address these issues. Utility Model Content

[0005] To overcome the above shortcomings, this utility model provides an adjustable fiber optic delay line, which aims to improve the problem that existing adjustable fiber optic delay lines only contain one round of optical path reflection and have a narrow adjustable range of optical path difference.

[0006] To achieve the above objectives, the present invention adopts the following technical solution:

[0007] An adjustable fiber optic delay line includes a base, a prism slidably mounted on the base, a fiber optic input section, and a fiber optic output section.

[0008] Along the length of the adjustable fiber delay line, the prism is slidably mounted on the base via an electric slide mechanism.

[0009] The reflector is fixed on the base, and the normal of the reflective surface of the reflector is parallel to the length direction.

[0010] The prism is a total internal reflection prism, with its incident surface perpendicular to its length direction. The incident light and the outgoing light corresponding to the incident light are parallel to each other but do not coincide.

[0011] A laser coupler, comprising a trunk fiber, a first branch fiber, and a second branch fiber.

[0012] The laser beam is input through the first branch optical fiber, and as the first incident light, it passes through the trunk optical fiber and is directed toward the prism. After undergoing the first round of total internal reflection inside the prism, it becomes the first outgoing light parallel to the first incident light and is directed toward the reflecting mirror.

[0013] After the first outgoing light is vertically reflected by the mirror, it enters the prism again as the second incident light. After undergoing a second round of total internal reflection, it becomes the second outgoing light parallel to the second incident light and is directed towards the main optical fiber. It then exits from the second branch optical fiber of the laser coupler.

[0014] It can be seen that by driving the prism to slide through an electric slide table, the external laser is reflected through the prism, waveplate and reflective mirror, which extends the optical path distance and achieves the same optical path difference adjustment range while reducing the prism sliding distance. This solves the problem that existing adjustable fiber delay lines only contain one round of optical path reflection and have a narrow optical path difference adjustment range, effectively saving internal space and realizing product miniaturization.

[0015] Furthermore, a laser polarization controller is installed on the side of the reflector closest to the prism.

[0016] The laser polarization controller is placed at the end of the incident light's optical path, which increases the distance between it and the laser coupler and reduces the interference feedback of the laser polarization controller to the laser coupler.

[0017] Furthermore, the laser polarization controller is a waveplate group, which includes waveplates arranged in sequence, with the first outgoing light and the second incident light perpendicular to the waveplates.

[0018] The waveplate itself generates reflected light. The waveplate is placed at the end of the incident light path to increase the offset distance of the reflected light relative to the exit port of the main optical fiber, weaken the reflected light entering the laser coupler, and reduce the interference of the reflected light on the output laser.

[0019] Furthermore, the waveplate is fixed on the rotating ring, which is rotatably mounted on the waveplate support. The waveplate support is fixed on the rib of the base, and the rotation axis of the rotating ring is parallel to the first emitted light.

[0020] The structure is simple, facilitating the installation and replacement of waveplates. The ribs also serve to support the base, increasing its rigidity and improving the stability and durability of the equipment.

[0021] Furthermore, the trunk optical fiber sends laser light to the prism through a collimator, which is mounted on the rib of the base via a mounting cylinder.

[0022] It facilitates improving the accuracy of the laser irradiation angle entering the prism in the trunk optical fiber and makes it easy to replace the laser coupler.

[0023] Furthermore, the reflector is fixed to the reflector bracket by a mounting ring, the reflector bracket is fixed to the mounting cylinder, the mounting cylinder is fixed to the mounting hole A of the rib, and the collimator is installed in the mounting hole B through the mounting cylinder.

[0024] It facilitates the installation and positioning of reflectors and standardized collimators, thereby improving production efficiency.

[0025] Furthermore, an adjustable gap is provided between the reflector bracket and the mounting cylinder, and an adjustable gap is provided between the collimator and the mounting cylinder.

[0026] Furthermore, the laser coupler is mounted on the base via a column.

[0027] The laser coupler is supported by a column and suspended in the air for easy heat dissipation.

[0028] Furthermore, the prism is a pyramidal prism or a Proto prism.

[0029] Prisms achieve optical path adjustment through total internal reflection, which simplifies optical path components, optimizes the compactness of equipment structure, and improves installation accuracy.

[0030] Furthermore, the electric slide mechanism includes a guide rail and a slide fixed on the base, a prism fixed on the slide, a motor fixed inside the base, a lead screw fixedly connected to the output end of the motor, the lead screw being rotatably connected inside the base, and a nut being rotatably connected to the outer wall of the lead screw, with the nut fixed to the slide.

[0031] Furthermore, multiple mounting tubes are fixedly connected to the base, and each mounting tube is fixedly connected to a sheath for passing optical fibers.

[0032] The sheath is used to pass through the first and second branch optical fibers. The sheath protects the optical fibers from external damage and extends the equipment's lifespan.

[0033] Furthermore, a control board is installed between the laser coupler and the motor.

[0034] It helps to reduce wiring distance, make full use of space, and facilitates Xiaoxinghua Street.

[0035] Furthermore, a control cable is fixedly connected to the base, and a cover is provided on the top of the base, with an observation window fixedly connected to the cover.

[0036] Control cables are used for signal transmission and equipment operation. The viewing window facilitates monitoring of equipment status, such as whether the motorized slide is functioning correctly and whether the laser is within the reflection zone.

[0037] This utility model has the following beneficial effects:

[0038] In this invention, the prism is driven to slide by an electric slide table, so that the external laser is reflected by the prism, the paddle plate and the reflective lens, thereby extending the optical path distance. This achieves the same optical path difference adjustment range while reducing the prism sliding distance, solving the problem that existing adjustable fiber delay lines only contain one round of optical path reflection and have a narrow optical path difference adjustment range. This effectively saves internal space and enables product miniaturization. Attached Figure Description

[0039] Figure 1 This is a three-dimensional schematic diagram of the adjustable fiber delay line proposed in this utility model.

[0040] Figure 2 This is a schematic diagram of the internal structure of the base of the adjustable fiber delay line proposed in this utility model.

[0041] Figure 3 This is a schematic diagram of the collimator structure for the adjustable fiber delay line proposed in this utility model.

[0042] Figure 4 This is a schematic diagram of the reflective lens structure of the adjustable fiber delay line proposed in this utility model. Detailed Implementation

[0043] 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.

[0044] Reference Figures 1-4 An adjustable fiber optic delay line includes a base 2, a prism 8 slidably mounted on the base 2, a fiber optic input section 101, and a fiber optic output section 102.

[0045] Along the length direction 01 of the adjustable fiber delay line, the prism 8 is slidably mounted on the base 2 via an electric slide mechanism 100.

[0046] The reflector 24 is fixed on the base 2, and the normal of the reflecting surface of the reflector 24 is parallel to the length direction O1.

[0047] Prism 8 is a total internal reflection prism, with its incident surface 81 perpendicular to the length direction 01. Its incident light and the outgoing light corresponding to the incident light are parallel to each other but do not coincide.

[0048] The laser coupler 12 includes a trunk fiber 120, a first branch fiber 121, and a second branch fiber 122.

[0049] The laser is input through the first branch fiber 121, and as the first incident light, it is directed to the prism 8 through the main fiber 120. After undergoing the first round of total internal reflection in the prism 8, it is directed to the reflector 24 as the first outgoing light parallel to the first incident light.

[0050] After the first outgoing light is vertically reflected by the reflector 24, it enters the prism 8 again as the second incident light. After undergoing a second round of total internal reflection, it is sent to the main optical fiber 120 as the second outgoing light parallel to the second incident light, and then exits from the second branch optical fiber 122 of the laser coupler 12.

[0051] It can be seen that by driving the prism to slide through an electric slide table, the external laser is reflected through the prism, waveplate and reflective mirror, which extends the optical path distance and achieves the same optical path difference adjustment range while reducing the prism sliding distance. This solves the problem that existing adjustable fiber delay lines only contain one round of optical path reflection and have a narrow optical path difference adjustment range, effectively saving internal space and realizing product miniaturization.

[0052] Furthermore, a laser polarization controller 230 is installed on the side of the reflector 24 near the prism 8.

[0053] Furthermore, the laser polarization controller 230 is a waveplate group, which includes 1 / 2 waveplates, 1 / 4 waveplates and 1 / 2 waveplates arranged in sequence, with the first outgoing light and the second incident light perpendicular to the waveplates.

[0054] Furthermore, the waveplate is fixed on the rotating ring 23, which is rotatably mounted on the waveplate support 19. The waveplate support 19 is fixed on the rib plate 22 of the base 2, and the rotation axis of the rotating ring is parallel to the first emitted light.

[0055] Furthermore, the trunk fiber 120 sends laser light to the prism 8 through the collimator 11, which is mounted on the rib 22 of the base 2 via the mounting cylinder 10.

[0056] Furthermore, the reflector 24 is fixed to the reflector bracket 16 by the mounting ring 26, the reflector bracket 16 is fixed to the mounting cylinder 10, the mounting cylinder 10 is fixed to the mounting hole A25 of the rib plate 22, and the collimator 11 is installed in the mounting hole B27 through the mounting cylinder 10.

[0057] Furthermore, an adjustable gap is provided between the reflector bracket 16 and the mounting cylinder 10, and an adjustable gap is provided between the collimator 11 and the mounting cylinder 10.

[0058] Furthermore, the laser coupler 12 is mounted on the base 2 via the column 13.

[0059] Furthermore, prism 8 is a pyramidal prism or a Proton prism.

[0060] Furthermore, the electric slide mechanism 100 includes a guide rail 9 and a slide 7 fixed on the base 2, a prism 8 fixed on the slide 7, a motor 4 fixed inside the base 2, a lead screw 5 fixedly connected to the output end of the motor 4, the lead screw 5 being rotatably connected inside the base 2, and a nut 6 being rotatably connected to the outer wall of the lead screw 5, the nut 6 being fixed to the slide 7.

[0061] Furthermore, multiple mounting tubes 17 are fixedly connected to the base 2, and each mounting tube 17 is fixedly connected to a sheath 18 for passing optical fibers.

[0062] The sheath 18 is used for the passage of the first branch optical fiber 121 and the second branch optical fiber 122.

[0063] Furthermore, a control board 14 is provided between the laser coupler 12 and the motor 4.

[0064] Furthermore, a control cable 15 is fixedly connected to the base 2, and a cover 1 is provided on the top of the base 2, with an observation window 3 fixedly connected to the cover 1.

[0065] Preferably, the mounting cylinder 10 is a gold-plated welded tube.

[0066] The aforementioned laser coupler 12 is not limited to the 1X2 type laser coupler described above, but can also be a 2X2 type laser coupler, which aims to separate the laser to be output from the same optical path. Therefore, the laser coupler can also be replaced by an isolator composed of a polarizing beam splitter crystal and a waveplate.

[0067] Specifically, an external laser beam is input through the fiber optic input section 101, entering the trunk fiber 120 on one side of the laser coupler 12 as the first incident light, and is transmitted to the prism 8. After undergoing a first round of total internal reflection inside the prism 8, the first incident light is emitted as a first outgoing light parallel to the first incident light and strikes the reflecting mirror 24. The reflecting mirror 24 reflects the first outgoing light perpendicularly, causing it to re-enter the surface of the prism 8 as a second incident light. After undergoing total internal reflection again inside the prism 8, the second incident light forms a second outgoing light parallel to the second incident light and is transmitted back to the trunk fiber optic section on one side of the laser coupler 12. The optical fiber 120 is then output from the optical fiber output unit 102 via the laser coupler 12, completing the transmission and adjustment of the optical signal. During this process, when the electric slide 7 drives the prism 8 to slide along the outer wall of the guide rail 9, the optical path difference increases by 4 mm for every 1 mm of sliding. This makes the increase in optical path difference twice that of the prior art. Since the optical path difference is linearly related to the displacement of the prism 8, this design significantly reduces the sliding distance of the prism 8. For example, within the same optical path difference adjustment range, the sliding distance of the prism 8 can be shortened by half, thereby effectively reducing the space occupied by the equipment and optimizing the miniaturization design of the device. In addition, by reducing the sliding stroke of the prism 8, not only is the stability and reliability of the equipment operation improved, but the efficiency of optical path difference adjustment is also improved. This structure fully utilizes the double-wheel total internal reflection characteristics of the prism 8 and optimizes the folding design of the optical path, balancing the adjustment capability of the optical path difference with the miniaturization requirements of the equipment, significantly improving the performance and applicability of the equipment.

[0068] Working principle: During the use of the equipment, an external laser is input through the fiber optic input section 101. As the first incident light, it passes through the trunk fiber 120 on one side of the laser coupler 12 and is directed towards the prism 8. After undergoing the first round of total internal reflection in the prism 8, it becomes the first outgoing light parallel to the first incident light and is directed towards the reflecting mirror 24. After being perpendicularly reflected by the reflecting mirror 24, the first outgoing light becomes the second incident light and re-enters the surface of the prism 8. After undergoing the second round of total internal reflection, it becomes the second outgoing light parallel to the second incident light and is directed towards the trunk fiber 120 on one side of the laser coupler 12. Subsequently, it is output from the fiber optic output section 102 through the laser coupler 12. When the electric slide table 7 drives the prism 8 to slide 1mm on the outer wall of the guide rail 9, the optical path difference increases by 4mm. The optical path difference is 4 times the displacement of the prism 8, which is twice that of the prior art. For the same optical path difference adjustment range, the sliding distance of the prism 8 can be reduced by half, which is beneficial for the miniaturization of the adjustable fiber delay line.

[0069] Finally, it should be noted that the above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. Although the present utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.

Claims

1. An adjustable fiber optic delay line, comprising a base (2), a prism (8) slidably mounted on the base (2), an optical fiber input section (101), and an optical fiber output section (102), characterized in that: Along the length direction (01) of the adjustable fiber delay line, the prism (8) is slidably mounted on the base (2) via an electric slide mechanism (100); A reflector (24) is fixed on the base (2), and the normal of the reflecting surface of the reflector (24) is parallel to the length direction (01); The prism (8) is a total internal reflection prism, whose incident surface (81) is perpendicular to the length direction (01), and whose incident light and the outgoing light corresponding to the incident light are parallel to each other but do not coincide; The laser coupler (12) includes a trunk fiber (120), a first branch fiber (121), and a second branch fiber (122). The laser is input through the first branch optical fiber (121), and as the first incident light, it is directed to the prism (8) through the trunk optical fiber (120). After undergoing the first round of total internal reflection in the prism (8), it is directed to the reflector (24) as the first outgoing light parallel to the first incident light. After the first outgoing light is vertically reflected by the reflector (24), it enters the prism (8) again as the second incident light. After undergoing a second round of total internal reflection, it is directed as the second outgoing light parallel to the second incident light and then exits from the second branch fiber (122) of the laser coupler (12).

2. The adjustable fiber delay line according to claim 1, characterized in that: A laser polarization controller (230) is installed on the side of the reflector (24) near the prism (8).

3. The adjustable fiber delay line according to claim 2, characterized in that: The laser polarization controller (230) is a waveplate group, which includes a 1 / 2 waveplate, a 1 / 4 waveplate and a 1 / 2 waveplate arranged in sequence, and the first outgoing light and the second incident light are perpendicular to the waveplates.

4. The adjustable fiber delay line according to claim 3, characterized in that: The waveplate is fixed on the rotating ring (23), which is rotatably mounted on the waveplate bracket (19). The waveplate bracket (19) is fixed on the rib (22) of the base (2), and the rotation axis of the rotating ring is parallel to the first emitted light.

5. The adjustable fiber delay line according to claim 2, characterized in that: The trunk optical fiber (120) sends laser light to the prism (8) through the collimator (11), which is mounted on the rib (22) of the base (2) through the mounting cylinder (10).

6. The adjustable fiber delay line according to claim 5, characterized in that: The reflector (24) is fixed to the reflector bracket (16) by the mounting ring (26), the reflector bracket (16) is fixed to the mounting cylinder (10), the mounting cylinder (10) is fixed to the mounting hole A (25) of the rib plate (22), and the collimator (11) is mounted in the mounting hole B (27) through the mounting cylinder (10).

7. The adjustable fiber delay line according to claim 6, characterized in that: An adjustable gap is provided between the reflector bracket (16) and the mounting cylinder (10), and an adjustable gap is provided between the collimator (11) and the mounting cylinder (10).

8. The adjustable fiber delay line according to claim 2, characterized in that: The laser coupler (12) is mounted on the base (2) via a column (13).

9. The adjustable fiber delay line according to any one of claims 1 to 5, characterized in that: The prism (8) is a pyramidal prism or a Proton prism.

10. The adjustable fiber delay line according to claim 9, characterized in that: The electric slide mechanism (100) includes a guide rail (9) and a slide (7) fixed on the base (2). The prism (8) is fixed on the slide (7). A motor (4) is fixed inside the base (2). A lead screw (5) is fixedly connected to the output end of the motor (4). The lead screw (5) is rotatably connected inside the base (2). A nut (6) is rotatably connected to the outer wall of the lead screw (5). The nut (6) is fixed to the slide (7).

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