Free space optical receiving system based on few-mode multi-core optical fiber

Abstract

The invention discloses a free space optical receiving system based on a few-mode multi-core optical fiber. The receiving system is characterized by comprising a receiving antenna, a few-mode multi-core optical fiber, a mode demultiplexer, a detector and a receiver. The invention aims to further develop a free space optical receiving system, and provides the free space optical receiving system based on the few-mode multi-core optical fiber. The system is characterized in that the characteristic of high tolerance of the few-mode multi-core optical fiber is fully utilized when the received lightbeams are not aligned. According to the invention, the coupling efficiency of free space light can be improved, and the influence caused by atmospheric turbulence disturbance is reduced, so that thebit error rate during signal demodulation is reduced. In addition, the requirement on the aiming tracking precision of the received light beam can be reduced, and the method has very important significance for free space optical receiving systems such as long-distance free space optical communication and laser radar.

Description

technical field [0001] The invention relates to a free-space optical receiving system, in particular to a free-space optical receiving system based on few-mode multi-core optical fibers. Background technique [0002] The free space optical receiving system is a means of coupling the light arriving at the receiving system into the receiver. At present, due to the development of optical fiber receivers, optical fiber reception has become a mainstream method. Among them, the single-mode fiber core diameter is too small, and the coupling efficiency is too low under the condition of atmospheric turbulence. Since multimode optical fibers receive hundreds of modes at the same time, subsequent processing is difficult. Recently, the reception method of few-mode fiber has attracted attention. [0003] Prior art [1] (D.H.Zheng, Y.Li, E.H.Chen, B.B.Li, D.M.Kong, W.Li, et al., "Free-space to few-mode-fiber coupling under atmospheric turbulence," OpticsExpress, vol .25, pp.18739-18755...

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Problems solved by technology

Few-mode multicore fiber (R.G.H.van Uden, R.A.Correa, E.A.Lopez, F.M.Huijskens, C.Xia, G. Li, et al.,"Ultra-high-density spatial division multiplexing with a few-mode multicore fiber,"Nature Photonics, vol.8, pp.865-870, Nov 2015.) has achieved great application in optical fiber communication, but the application in free-light optical system is still blank

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