A high-power collimated optical adapter that isolates receiver reflections
By using a two-stage optical isolator with double-sided air-coated Faraday rotators and yttrium vanadate crystal wedges in the isolator, combined with a collimating lens, the problems of assembly deviation and complex optical path coupling in the prior art are solved, realizing a high-power optical adapter with high isolation and low insertion loss, which is suitable for high-power fiber optic communication and lidar systems.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- SICHUAN SHENGJIE OPTOELECTRONICS CO LTD
- Filing Date
- 2025-07-08
- Publication Date
- 2026-07-10
AI Technical Summary
Existing free-space isolators suffer from significant impacts from assembly deviations and cumbersome optical path coupling, making them unsuitable for high-power applications. Furthermore, polarization direction deviations result in low isolation, failing to effectively protect optical components at high power levels.
A two-stage optical isolator is fabricated using a double-sided air-coated Faraday rotator and a yttrium vanadate crystal wedge plate. Combined with a collimating lens, it forms an integrated structure, achieving polarization-independent two-stage isolation. It is resistant to high power and has high thermal conductivity, simplifying the optical path coupling process.
It achieves isolation of over 50dB and insertion loss of less than 0.3dB, enabling use at high power of 2W, simplifying optical path coupling process, reducing costs and improving product reliability.
Smart Images
Figure CN224480631U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of optical isolation adapter technology, and in particular to a high-power collimated optical adapter that isolates reflections from the receiver. Background Technology
[0002] Isolation adapters are primarily used for fiber optic port connections in fiber optic communication and lidar systems. They prevent light reflection caused by abrupt changes in refractive index at the interface during communication, thus protecting the transmitting signal from interference from reflected light and providing a low-loss connection to the fiber optic end. Currently, most isolators in the industry use polarization-dependent single-pole free-space isolators. The manufacturing process requires consideration of polarization direction markings and assembly deviations. If the deviation is slightly large, the isolation is only around 30 dB or even lower, and the insertion loss is difficult to reach 0.5 dB. Free-space isolators lack optical path collimation capabilities. During use, optical path coupling must rely on collimators before and after, forming a segmented structure requiring step-by-step coupling. This results in complex manufacturing processes at the manufacturer's site, and the optical path needs to be coupled again at the customer's application, leading to increased costs and waste. With the increase in laser power, free-space isolators face challenges in power tolerance. At high power densities, the surface of optical components is easily damaged by microparticles or thermal effects. High power causes device temperature rise, making them unsuitable for high-power scenarios and typically only applicable to scenarios below 500mW. Utility Model Content
[0003] To address the problems of existing free-space isolators, such as significant impact from assembly deviations, cumbersome optical path coupling, and inability to be used in high-power scenarios, this invention provides a high-power collimated optical adapter that isolates reflections from the receiving end.
[0004] This utility model provides the following technical solution: a high-power collimating optical adapter for isolating receiver reflections, comprising a housing, one end of which is provided with an optical fiber insertion slot, and the other end of which is provided with an isolator mounting slot. A lens mounting slot is provided at the end of the isolator mounting slot facing the optical fiber insertion slot, and the optical fiber insertion slot, lens mounting slot, and isolator mounting slot are connected. A magnetic ring is provided inside the isolator mounting slot, and two optical isolators are sequentially arranged along the axial direction within the magnetic ring cavity. Each optical isolator includes a Faraday rotator with air-coated surfaces on both sides, and wedge plates respectively disposed on both sides of the Faraday rotator. The wedge plates are made of yttrium vanadate crystal. A collimating lens is provided inside the lens mounting slot.
[0005] Preferably, a connecting hole is provided between the lens mounting slot and the fiber insertion slot, and the diameter of the connecting hole is smaller than the smaller of the diameter of the lens mounting slot and the diameter of the fiber insertion slot; the diameter of the lens mounting slot is smaller than the diameter of the isolator mounting slot.
[0006] Preferably, the magnetic ring is a U-shaped magnetic ring.
[0007] The beneficial effects of this invention are as follows: A dual-stage optical isolator is constructed using a double-sided air-coated Faraday rotator and a yttrium vanadate crystal wedge plate, forming a polarization-independent two-stage isolation function. This achieves an isolation level of over 50dB and reduces insertion loss to below 0.3dB, enabling the transmission of light in any polarization state without any reduction in isolation due to polarization direction deviation. The yttrium vanadate crystal possesses high power tolerance and high thermal conductivity, allowing it to be used in high-power scenarios up to 2W. Embedding a collimating lens within the housing to form an integrated structure simplifies the segmented coupling process during manufacturing and facilitates quick and easy installation at the customer's location, saving costs. Attached Figure Description
[0008] Figure 1 This is a cross-sectional view of one embodiment of a high-power collimated optical adapter.
[0009] Reference numerals: 10-Outer shell, 11-Fiber optic insertion slot, 12-Isolator mounting slot, 13-Lens mounting slot, 14-Connection hole, 21-Magnetic ring, 22a-Faraday rotator, 22b-Faraday rotator, 23a-Wedge plate, 23b-Wedge plate, 23c-Wedge plate, 23d-Wedge plate, 31-Collimating lens. Detailed Implementation
[0010] The embodiments of this utility model will be described in more detail below with reference to the accompanying drawings and reference numerals, so that those skilled in the art can implement them after reading this specification. It should be understood that the specific embodiments described herein are only for explaining this utility model and are not intended to limit this utility model.
[0011] This utility model provides, for example Figure 1 The high-power collimating optical adapter shown includes a housing 10 and a dual-stage optical isolator and a collimating lens disposed within the housing 10.
[0012] One end of the outer casing 10 is provided with an optical fiber insertion slot 11, into which an optical fiber is inserted. The other end is provided with an isolator mounting slot 12 for mounting a dual-stage optical isolator. A lens mounting slot 13 is provided at the end of the isolator mounting slot 12 facing the optical fiber insertion slot 11 for mounting a collimating lens 31. The diameter of the lens mounting slot 13 is smaller than that of the isolator mounting slot 12, forming a stepped limiting structure to restrict the insertion depth of the dual-stage optical isolator. A connecting hole 14 is also provided between the lens mounting slot 13 and the optical fiber insertion slot 11. The diameter of the connecting hole 14 is smaller than the smaller of the diameters of the lens mounting slot 13 and the optical fiber insertion slot 11, forming a stepped limiting structure between the connecting hole 14 and both the lens mounting slot 13 and the optical fiber insertion slot 11, restricting the insertion position of the collimating lens 31 and the optical fiber. The optical fiber insertion slot 11, the connecting hole 14, the lens mounting slot 13, and the isolator mounting slot 12 are connected, allowing light to pass through them.
[0013] The dual-stage optical isolator includes a magnetic ring 21 disposed within the isolator mounting slot. A first optical isolator and a second optical isolator are sequentially arranged along the axial direction within the magnetic ring 21. The magnetic ring 21 can be a U-shaped magnetic ring with a U-shaped cross-section. The first optical isolator includes a Faraday rotator 22a with air-coated sides, and wedge plates 23a and 23b respectively disposed on both sides of the Faraday rotator 22a. The second optical isolator includes a Faraday rotator 22b with air-coated sides, and wedge plates 23c and 23d respectively disposed on both sides of the Faraday rotator 22b. The wedge plates 23a-23d are all made of yttrium vanadate (YVO4) crystal, possessing birefringence, high power tolerance, and high thermal conductivity, enabling use in high-power scenarios up to 2W. The wedge angle, diameter, and other parameters of the wedge plates can be designed as needed.
[0014] A two-stage optical isolator provides polarization-independent two-stage isolation, allowing the transmission of light in any polarization state without any reduction in isolation due to polarization deviation. Forward light, such as... Figure 1 As indicated by the arrow, the light emitted from the fiber inserted in the fiber insertion slot 11 is divergent. After being collimated by the collimating lens 31, it passes through the double-stage optical isolator. The reflected light is in the opposite direction to the forward light. When the forward light enters the double-stage optical isolator, birefringence occurs. After passing through the double-stage optical isolator, ordinary light (O-ray) and extraordinary light (E-ray) are formed on its left side, both with their exit directions parallel to the incident light. The O-ray and E-ray generated by the reflection light entering the double-stage optical isolator diverge outward, thus protecting the laser and optical amplifier from interference from reflected light.
[0015] In such Figure 1The collimating optical adapter shown has a light source on the right side to simulate forward light and a power meter on the left side. The test results show that its forward optical path insertion loss is below 0.3dB. Then, a power meter is set on the right side of the collimating optical adapter, and a light source is set on the left side to simulate reflected light. The test results show that its reverse optical path isolation is above 50dB.
[0016] The above describes one or more embodiments of this utility model in a relatively specific and detailed manner, but it should not be construed as limiting the scope of this utility model patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this utility model, and these all fall within the protection scope of this utility model. Therefore, the protection scope of this utility model patent should be determined by the appended claims.
Claims
1. A high-power collimated optical adapter that isolates receiver reflections, characterized in that, The device includes a housing, one end of which has an optical fiber insertion slot, and the other end has an isolator mounting slot. A lens mounting slot is located at the end of the isolator mounting slot facing the optical fiber insertion slot, and the optical fiber insertion slot, lens mounting slot, and isolator mounting slot are connected. A magnetic ring is located within the isolator mounting slot, and two optical isolators are sequentially arranged along the axial direction within the magnetic ring's inner cavity. Each optical isolator includes a Faraday rotator with air-coated surfaces on both sides, and wedge plates respectively disposed on both sides of the Faraday rotator. The wedge plates are made of yttrium vanadate crystal. A collimating lens is located within the lens mounting slot.
2. A high-power collimated optical adapter for isolating receiver reflections according to claim 1, characterized in that, A connecting hole is also provided between the lens mounting slot and the fiber insertion slot, and the diameter of the connecting hole is smaller than the smaller value between the diameter of the lens mounting slot and the diameter of the fiber insertion slot; the diameter of the lens mounting slot is smaller than that of the isolator mounting slot.
3. A high-power collimated optical adapter for isolating receiver reflections according to claim 1, characterized in that, The magnetic ring is a U-shaped magnetic ring.