High-reliability single-channel polarization maintaining optical fiber rotary connector

Abstract

The utility model discloses a kind of high-reliability single-channel polarization maintaining optical fiber rotary connectors, comprising: first optical waveguide, second optical waveguide, first collimator, second collimator, first polarization converter and second polarization converter;The polarized light output by the first optical waveguide is coupled to first polarization converter;The first polarization converter is used to convert linearly polarized light into circularly polarized light;Circularly polarized light is sent into second collimator by first collimator, and the second collimator is rotatable relative to first collimator, and the second polarization converter is connected with second collimator, and rotates together;The second polarization converter converts circularly polarized light into linearly polarized light and is coupled into second optical waveguide.The utility model can realize 360 degrees unlimited rotation, and polarization maintaining optical signal can be transmitted simultaneously, and the uninterrupted transmission of optical signal is realized.The utility model effectively reduces optical signal polarization loss, reduces optical signal echo loss in rotation process.

Description

Technical Field

[0001] This utility model belongs to the field of optical fiber connector technology, and specifically relates to a highly reliable single-channel polarization-maintaining optical fiber rotary connector. Background Technology

[0002] High bit rate transmission systems tend to transmit optical signals in a polarization-maintaining manner; however, in fields such as energy, defense, industry, and medicine, it is often necessary to transmit data uninterruptedly from one rotating platform to another stationary platform. For these two reasons, fiber optic connectors that can transmit polarization-maintaining optical signals uninterruptedly between rotatable units are of great significance.

[0003] Various transmission systems are known for transmitting optical signals between rotatable units. These include Dove prisms and multiple reflections from mirror-coated trenches. However, the polarization state of the coupled light changes during the rotation of a Dove prism, and the polarization state changes with the reflection position and number of reflections. None of these systems can satisfy the requirement for uninterrupted rotational transmission of polarized light. Utility Model Content

[0004] To address the aforementioned technical problems, this invention provides a highly reliable single-channel fiber optic rotary connector capable of transmitting polarization-maintaining optical signals between rotating platforms.

[0005] To achieve the above objectives, the present invention adopts the following technical solution: a highly reliable single-channel polarization-maintaining fiber optic rotary connector, the device comprising: a first optical waveguide, a second optical waveguide, a first collimator, a second collimator, a first polarization converter, and a second polarization converter;

[0006] The first optical waveguide is connected to the first polarization converter, coupling the output polarized light to the first polarization converter; the first polarization converter is connected to the first collimator, and they rotate together; the first polarization converter converts linearly polarized light into circularly polarized light; the circularly polarized light is sent to the second collimator through the first collimator, the second collimator is rotatable relative to the first collimator, the second polarization converter is connected to the second collimator, and they rotate together; the second polarization converter converts the circularly polarized light into linearly polarized light and couples it into the second optical waveguide.

[0007] Furthermore, it also includes a first bracket and a second bracket, wherein the first polarization converter and the first collimator are mounted on the first bracket and rotate together, and the second polarization converter and the second collimator are mounted on the second bracket and rotate together.

[0008] Furthermore, the first polarization converter and the second polarization converter are birefringent single-crystal waveplates, specifically quarter-waveplates, with a waveplate thickness such that when light is incident from the normal direction through the waveplate, the phase difference between the ordinary ray and the extraordinary ray is equal to π / 2 or an odd multiple thereof.

[0009] Furthermore, the first and second collimators are equipped with lenses.

[0010] Furthermore, the propagation space between the first collimator and the second collimator is a gas or liquid.

[0011] Furthermore, at least one of the first polarization converter and the second polarization converter has an anti-reflective coating.

[0012] Furthermore, at least one of the first polarization converter and the second polarization converter is tilted to be at an angle to the incident beam.

[0013] Furthermore, the first polarization converter and the second polarization converter are surrounded by solid optical material.

[0014] Compared with the prior art, the present invention has the following beneficial effects:

[0015] This invention relates to a highly reliable single-channel polarization-maintaining fiber optic rotary connector that allows for unrestricted 360-degree rotation while simultaneously transmitting polarization-maintaining optical signals, achieving uninterrupted optical signal transmission. This invention effectively reduces optical signal polarization loss and minimizes optical signal return loss during rotation. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the structure of this utility model;

[0017] Figure 2 This is a three-dimensional structural diagram of the present invention.

[0018] In the figure: 1-First collimator, 2-First optical waveguide, 3-First polarization converter, 4-First support, 5-Free space optical path, 6-Rotation axis (z-axis), 7-Second collimator, 8-Second optical waveguide, 9-Second polarization converter, 10-Second support. Detailed Implementation

[0019] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, and not all embodiments. Based on the single embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of this utility model.

[0020] 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.

[0021] In the following sections, for simplicity, we will also discuss the incident surface of light, light coupling, etc. It goes without saying that when the transmission directions are opposite, these terms will apply to the corresponding exit surface of light, etc. In one embodiment, one or more hollow spaces inside the device may be filled with air, gas, or even a liquid, such as oil. Therefore, the term free-space propagation will also apply to one or a combination of these media.

[0022] Reference Figure 1 A highly reliable single-channel polarization-maintaining fiber optic rotary connector includes a first unit and a second unit. The first unit includes a first collimator 1, a first optical waveguide 2, a first polarization converter 3, and a first support 4. The second unit includes a second collimator 7, a second optical waveguide 8, a second polarization converter 9, and a second support 10.

[0023] The first bracket is equipped with a first collimator 1 and a first polarization converter 3, and the second bracket 10 is equipped with a second collimator 7 and a second polarization converter 9.

[0024] The function of a collimator is to achieve the interconversion of stable light transmission in optical fibers and free space. It is used for beam guiding or beam shaping. Other collimators that can achieve this function include, but are not limited to, micro-optical elements. Preferably, the collimator incorporates a lens, possibly a microlens. The second collimator 7 is rotatable relative to the first collimator 1 about a rotation axis 6 (also referred to here as the z-axis). Figure 1 and Figure 2 The central rotation axis 6 is represented by two line segments 6a and 6b, and is not drawn as passing through the entire rotating data transmission device. The collimators are aligned with each other, and the free-space optical path 5 is between them.

[0025] The first polarization converter 3 converts linearly polarized light into circularly polarized light, which is then input into the first collimator 1. The first polarization converter is connected to the first collimator and rotates together with it. The second polarization converter 9 converts circularly polarized light from the second collimator into linearly polarized light. The second polarization converter is connected to the second collimator and rotates together with it, thus rotating relative to each other along with the first polarization converter and the first collimator. The polarization converters and the optical waveguide, or the optical waveguide with the attached collimator, must be rotated and adjusted relative to each other so that the polarization angle of the optical fiber is suitable for the polarization converter.

[0026] The first optical waveguide 2 is installed at the optical input end of the first bracket 4 and connected to the first polarization converter 3, which couples the linearly polarized light of the first unit from the first optical waveguide 2 to the first polarization converter 3.

[0027] The second optical waveguide 8 is installed at the optical output end of the second bracket 10 and connected to the second polarization converter 3, coupling the linearly polarized light output by the second polarization converter 9 into the second optical waveguide 8.

[0028] The function of a polarization converter is to convert between linearly polarized and circularly polarized light. A quarter-wave plate is preferred; it is a birefringent single-crystal waveplate with a specific thickness such that when light is incident normally through the waveplate, the phase difference between the ordinary ray (o-ray) and the extraordinary ray (e-ray) is equal to π / 2 or an odd multiple thereof. When linearly polarized light is incident perpendicularly to the quarter-wave plate, and the polarization of the light is at 45° to the optical axis of the quarter-wave plate, the emitted light is circularly polarized. Similarly, circularly polarized light can also be converted to linearly polarized light. Other polarization converters that can achieve this function include, but are not limited to, liquid crystals and photonic crystals.

[0029] The polarization converter is surrounded by glass, silicon, germanium or any other solid optical material, which further reduces reflections on the polarization converter surface and lowers the system's return loss.

[0030] Furthermore, preferably, at least one of the first polarization converter 3 and the second polarization converter 9 is tilted to form an oblique angle with the incident beam. For this purpose, due to the resulting larger layer thickness, it must conform to the wavelength used in the design.

[0031] This embodiment also provides a usage process for a high-reliability single-channel polarization-maintaining fiber optic rotary connector, used for polarization-maintaining transmission of linearly polarized light between a first unit and a second unit that can rotate relative to the first unit. Specifically:

[0032] (1) The linearly polarized light of the first unit is coupled from the first optical waveguide 2 to the first polarization converter 3;

[0033] (2) Use the first polarization converter 3 of the first unit to convert linearly polarized light into circularly polarized light;

[0034] (3) A spatially parallel beam is generated from circularly polarized light through the first collimator 1;

[0035] (4) Light is coupled from the first unit to the second unit through the free space optical path 5;

[0036] (5) Focus the parallel beam using the second collimator 7;

[0037] (6) Use the second polarization converter 9 of the second unit to convert the circularly polarized light from the second collimator 7 into linearly polarized light;

[0038] (7) Couple the linearly polarized light into the second optical waveguide 8.

[0039] The rotary connector can operate in both directions, from the first collimator to the second collimator or vice versa.

[0040] The above embodiments are used to explain and illustrate the present utility model, and are not intended to limit the present utility model. Any modifications and changes made to the present utility model within the spirit and scope of the claims shall fall within the protection scope of the present utility model.

Claims

1. A highly reliable single-channel polarization-maintaining fiber optic rotary connector, characterized in that, include: First optical waveguide, second optical waveguide, first collimator, second collimator, first polarization converter, and second polarization converter; The first optical waveguide is connected to the first polarization converter, coupling the output polarized light to the first polarization converter; the first polarization converter is connected to the first collimator, and they rotate together; the first polarization converter converts linearly polarized light into circularly polarized light; the circularly polarized light is sent to the second collimator through the first collimator, the second collimator is rotatable relative to the first collimator, the second polarization converter is connected to the second collimator, and they rotate together; the second polarization converter converts the circularly polarized light into linearly polarized light and couples it into the second optical waveguide.

2. The high-reliability single-channel polarization-maintaining fiber optic rotary connector according to claim 1, characterized in that, It also includes a first bracket and a second bracket. The first polarization converter and the first collimator are mounted on the first bracket and rotate together. The second polarization converter and the second collimator are mounted on the second bracket and rotate together.

3. A high-reliability single-channel polarization-maintaining fiber optic rotary connector according to claim 1, characterized in that, The first polarization converter and the second polarization converter are birefringent single-crystal waveplates, specifically quarter-waveplates. The thickness of the waveplate is such that when light is incident from the normal direction through the waveplate, the phase difference between the ordinary ray and the extraordinary ray is equal to π / 2 or an odd multiple thereof.

4. A high-reliability single-channel polarization-maintaining fiber optic rotary connector according to claim 1, characterized in that, The first collimator and the second collimator are equipped with lenses.

5. A high-reliability single-channel polarization-maintaining fiber optic rotary connector according to claim 1, characterized in that, The propagation space between the first collimator and the second collimator is a gas or liquid.

6. A high-reliability single-channel polarization-maintaining fiber optic rotary connector according to claim 1, characterized in that, At least one of the first polarization converter and the second polarization converter has an anti-reflective coating.

7. A high-reliability single-channel polarization-maintaining fiber optic rotary connector according to claim 1, characterized in that, At least one of the first polarization converter and the second polarization converter is tilted to be at an angle to the incident beam.

8. A high-reliability single-channel polarization-maintaining fiber optic rotary connector according to claim 1, characterized in that, The first polarization converter and the second polarization converter are surrounded by solid optical material.

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