CN-122018186-A - Double-stage optical isolator sharing magnet

CN122018186ACN 122018186 ACN122018186 ACN 122018186ACN-122018186-A

Abstract

The invention provides a double-stage optical isolator sharing a magnet, which comprises a magnet, two optical isolator cores and an optical path turning-back component, wherein a magnetic field space is formed inside the magnet, the optical isolator cores comprise a polarization beam splitter, a half wave plate, faraday optical rotation crystals and a polarization beam splitter which are sequentially arranged along a forward optical path, the two Faraday optical rotation crystals are arranged in the magnetic field space of the same magnet, the input end of the optical path turning-back component is used for receiving combined light output by a second polarization beam splitter, and the output end of the optical path turning-back component is used for outputting the combined light to a third polarization beam splitter. The two Faraday optical crystals share the uniform magnetic field space provided by the same set of magnet, so that a set of magnet assembly is omitted, the cost of expensive magnetic materials is obviously reduced, and the whole volume and the weight, particularly the axial length of the device are greatly reduced due to the reduction of the space occupied by the set of magnet and the mounting structure of the magnet, so that the miniaturization and the light weight of the device are realized.

Inventors

DENG JIANQIN
WU HAOQIAN
HUANG HANKAI
XIE NANJIE
WANG JIANQIANG
HAO TING
ZHAO XI
WU WANLING
HU YANBIN

Assignees

珠海光库科技股份有限公司

Dates

Publication Date: 20260512
Application Date: 20260130

Claims (7)

1. The double-stage optical isolator sharing the magnet is characterized by comprising a set of magnet, a first optical isolator core, a second optical isolator core and an optical path turning-back component, wherein a magnetic field space is formed inside the magnet; the first optical isolator core comprises a first polarization beam splitter, a first half-wave plate, a first Faraday rotator crystal and a second polarization beam splitter which are sequentially arranged along a first forward optical path; the second optical isolator core comprises a third polarization beam splitter, a second half-wave plate, a second Faraday rotator crystal and a fourth polarization beam splitter which are sequentially arranged along a second forward optical path; the first forward light path and the second forward light path are arranged in parallel in the same direction; The first Faraday optical rotation crystal and the second Faraday optical rotation crystal are both arranged in the magnetic field space of the same magnet; The input end of the light path turning-back component is used for receiving the combined beam light output by the second polarization beam splitter, and the output end of the light path turning-back component is used for outputting the combined beam light to the third polarization beam splitter.
2. The dual stage optical isolator of claim 1, wherein: The optical path returning component comprises a first reflecting prism and a second reflecting prism, wherein the first reflecting prism is arranged at the rear stage of the second polarization beam splitter based on the first forward optical path, and the second reflecting prism is arranged at the front stage of the third polarization beam splitter based on the second forward optical path; The first reflecting prism is used for receiving the combined beam output by the second polarizing beam splitter, the first reflecting prism is used for outputting the combined beam to the second reflecting prism, and the second reflecting prism is used for outputting the combined beam to the third polarizing beam splitter.
3. The dual stage optical isolator of claim 2, wherein: The first reflecting prism and the second reflecting prism are right-angle reflecting prisms, the first reflecting prism comprises a first reflecting surface and a second reflecting surface which are perpendicular to each other, the second reflecting prism comprises a third reflecting surface and a fourth reflecting surface which are perpendicular to each other, the first reflecting surface is opposite to the second polarizing beam splitter, the second reflecting surface is opposite to the third reflecting surface, and the fourth reflecting surface is opposite to the third polarizing beam splitter.
4. The dual stage optical isolator of claim 1, wherein: The dual stage optical isolator further includes an input collimator disposed in front of the first polarizing beam splitter based on the first forward optical path.
5. The dual stage optical isolator of claim 1, wherein: The first Faraday optically active crystal and the second Faraday optically active crystal are arranged side by side, and a magnetic flux passing through the first Faraday optically active crystal is the same as a magnetic flux passing through the second Faraday optically active crystal.
6. The dual stage optical isolator of any one of claims 1 to 5, wherein: The magnets are annularly arranged.
7. The dual stage optical isolator of any one of claims 1 to 5, wherein: the magnet includes a first magnet and a second magnet, and the magnetic field space is formed between the first magnet and the second magnet.

Description

Double-stage optical isolator sharing magnet Technical Field The invention relates to the technical field of passive optical devices, in particular to a double-stage optical isolator sharing a magnet. Background The optical isolator is a key passive device in optical communication, laser processing and precision optical systems, and has the core function of allowing unidirectional transmission of optical signals, thereby effectively isolating interference and damage of reverse light to a light source. In order to achieve a higher isolation index, a scheme of cascading two-stage optical isolation units is generally adopted in the industry. In the prior art, each isolator core is provided with a separate set of permanent magnet assemblies for generating the axial magnetic field required by the faraday rotator crystal. The traditional architecture of the two sets of magnets, while achieving corresponding functions, also brings about significant drawbacks. Firstly, two sets of high-performance permanent magnets directly push up the material cost, secondly, the magnets and the matched structures thereof lead the whole device, especially the size and the weight to be increased, furthermore, the two sets of magnets not only have the risk of mutual interference of magnetic fields in a limited packaging space, influence the performance stability, but also bring great complexity to assembly and debugging, the consistency of the space relative positions, the magnetic field directions and the magnetic field intensity of the two sets of magnets is required to be accurately ensured, the process requirement is harsh, and the production efficiency is low. Therefore, there is a need to design a dual stage optical isolator that overcomes the inherent drawbacks of the multi-magnet architecture described above while ensuring high performance. Disclosure of Invention The invention aims to provide a double-stage optical isolator sharing a magnet. The invention provides a double-stage optical isolator sharing a magnet, which comprises a set of magnet, a first optical isolator core, a second optical isolator core and an optical path turning-back component, wherein a magnetic field space is formed inside the magnet, the first optical isolator core comprises a first polarization beam splitter, a first half wave plate, a first Faraday rotator and a second polarization beam splitter which are sequentially arranged along a first forward optical path, the second optical isolator core comprises a third polarization beam splitter, a second half wave plate, a second Faraday rotator and a fourth polarization beam splitter which are sequentially arranged along a second forward optical path, the first forward optical path and the second forward optical path are arranged in parallel in the same direction, the first Faraday rotator and the second Faraday rotator are both arranged in the magnetic field space of the same magnet, the input end of the optical path turning-back component is used for receiving combined light output by the second polarization beam splitter, and the output end of the optical path turning-back component is used for outputting combined light to the third polarization beam splitter. The optical path turning-back component comprises a first reflecting prism and a second reflecting prism, wherein the first reflecting prism is arranged at the rear stage of the second polarizing beam splitter based on the first forward optical path, the second reflecting prism is arranged at the front stage of the third polarizing beam splitter based on the second forward optical path, the first reflecting prism is used for receiving the combined beam output by the second polarizing beam splitter, the first reflecting prism is used for outputting the combined beam to the second reflecting prism, and the second reflecting prism is used for outputting the combined beam to the third polarizing beam splitter. In a further scheme, the first reflecting prism and the second reflecting prism are right-angle reflecting prisms, the first reflecting prism comprises a first reflecting surface and a second reflecting surface which are perpendicular to each other, the second reflecting prism comprises a third reflecting surface and a fourth reflecting surface which are perpendicular to each other, the first reflecting surface is opposite to the second polarizing beam splitter, the second reflecting surface is opposite to the third reflecting surface, and the fourth reflecting surface is opposite to the third polarizing beam splitter. In a further aspect, the dual stage optical isolator further includes an input collimator disposed in front of the first polarizing beam splitter based on the first forward optical path. Still further, the first faraday-rotation crystal and the second faraday-rotation crystal are arranged side by side, and a magnetic flux passing through the first faraday-rotation crystal is the same as a magnetic flux passing through the seco