Polarizing beam-splitting birefringence space light bridge

Abstract

The invention relates to a polarizing beam-splitting birefringence space light bridge, which is characterized by consisting of a first 1 / 8 wave plate, a second 1 / 8 wave plate, a polarizing beam splitter, a first birefringence optical flat and a second birefringence optical flat, wherein the first 1 / 8 wave plate, a first incident face of the polarizing beam splitter, a first emergent face and the first birefringence optical flat are arranged in turn along the advancing direction of a first light beam; the second 1 / 8 wave plate, a second incident face of the polarizing beam splitter, a second emergent face and the second birefringence optical flat are arranged in turn along the advancing direction of a second light beam; and the main cross section of the first birefringence optical flat is parallel to the main cross section of the first 1 / 8 wave plate, and the main cross section of the second birefringence optical flat is parallel to the main cross section of the second 1 / 8 wave plate. The polarizing beam-splitting birefringence space light bridge has the advantages of compact structure, stable performance, adjustable phase and the like, and is applicable to a coherent laser communication system with free space transmission.

Description

technical field [0001] The present invention relates to coherent laser communication, specifically a two-way input and four-way output phase-adjustable polarization beam-splitting birefringent spatial optical bridge. The polarization beam splitter spatially couples two input beams and splits them into four combined beams for output. The / 8 wave plate produces an adjustable phase shift, which is used in coherent laser communication for spatially recombining laser signal beams and local oscillator laser beams, and produces a 90-degree 2×4 spatial optical bridge that can be phase-controlled as required. Background technique [0002] Space-borne laser communication terminals with large capacity, high bit rate, small size, light weight and low power consumption have great application prospects in both military and civilian applications. Since the receiver sensitivity of coherent laser communication is more than an order of magnitude higher than that of incoherent optical communic...

AI Technical Summary

Problems solved by technology

In the optical fiber communication system, the optical bridge is implemented by using the integration of optical fiber and waveguide, but these optical bridges suitable for the optical fiber communication system cannot meet the needs of space laser communication, and do not belong to the space optical bridge, because in free space laser communication In the system, the received optical signal is not only used to detect communication information, but also to extract position information for optical precision tracking. For free space laser communication terminals, the optical bridge must be free in space.

In free-space optical bridging, prior art [1], [2] (see document 1: Walter R.leeb.Realization of90°and 180°Hybrids for Optical Frequencies[C]. , Band 37[1983], Heft5 / 6: 203-206. Literature 2: R.Garreis, C.Zeiss, "90°optical hybrid for coherent receivers," Proc.SPIE, Vol.1522, pp.210-219, 1991 .) Proposed a 2×2 spatial optical bridge scheme using a polarizing beam splitter combined with a 1 / 4 wave plate, and a non-polarizing beam splitter combined with a 1 / 4 wave plate to achieve 90-degree and 180-degree phase shifts. Literature [2] states On this basis, a 2×4 90-degree phase shift implementation scheme is proposed, but this scheme has the disadvantages that the entire optical system needs to ensure the strict equal optical path transmission of the beam, there are too many related components, and it is not easy to integrate.

Prior technology [3], [4] (refer to document 3: Liu Liren, Liu Dean, Yan Aimin, Luan Zhu, Wang Lijuan, Sun Jianfeng, Zhong Xianghong, Electronically controlled phase-shift space optical bridge, invention patent, announcement number: 100383572, the same name is practical New patent announcement number: 200959599; document 4: Liu Liren, Yan Aimin, Luan Zhu, Liu Dean, Sun Jianfeng, Wang Lijuan, Zhong Xianghong, birefringent free-space optical bridge, invention patent, announcement number: 100383571, utility model patent announcement number 2899300) Another 2×4 90-degree space optical bridge solution is proposed by comprehensively utilizing the birefringence effect and electro-optic effect of the crystal. Although it solves the shortcomings of the prior art [1] and [2] that there are too many related components and it is not easy to integrate, but in The prior art [3] has the disadvantage that it is necessary to apply voltage to each chip and adjust the voltage when performing phase control, and the process is complicated, while the prior art [4] has the disadvantage of not being able to perform phase control

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