Ultrafast optical polarization scrambler

Abstract

An ultra-fast optical polarization scrambler is provided, which belongs to the field of optical fiber communication and optical engineering. A conventional optical polarization scrambler consists of a LiNbO3 wave guide or a plurality of wave plates, can scramble the polarization based on electrooptical effect or mechanical rotation, but has low speed of polarization scrambling. The invention provides an ultra-fast polarization scrambling technique based on nonlinear four-wave mixing effect. The technique is characterized in that the technique can produce idle frequency lights with random distribution of polarization state based on the four-wave mixing of polarized signal lights and non-polarized pump lights. The simulated experiment shows that the invention can produce idle frequency lights with random distribution of polarization state for any specified polarized signal, and the polarization state can substantially cover the Banka ball uniformly. The preliminary experiment shows thatthe polarized signal light and the non-polarized pump light can interact to efficiently form idle frequency light. The scrambling speed of the polarization scrambler is determined in the nonlinear four-wave mixing process of optical fibers and reaches the femto-second level.

Description

technical field [0001] The invention belongs to the field of optical fiber communication and optical engineering. Background technique [0002] In high-speed long-distance optical fiber communication systems, the polarization-dependent damage caused by the polarization of light cannot be ignored, such as polarization-mode dispersion in optical fibers, polarization-dependent loss in passive optical devices, and polarization-dependent gain in optical amplifiers have received extensive attention in recent years. In order to eliminate polarization-dependent damage, the use of a polarization scrambler has been proven to be an effective means (E.Lichtman, "Limitations imposed by polarization-dependent gain and lossonall-optical ultralong communication systems," J.Lightwave Technol.13, 906-913( 1995)). The working principle of the polarizer is to continuously change the polarization state of the polarized light passing through the polarizer at a high speed, so that in the overall...

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Problems solved by technology

The usual polarizer is made of LiNbO 3 Waveguide (H.Fred and W.S.Robert, "High-Speed ​​Polarization Scrambler with Adjustable Phase Chirp," J.Sel.Topics Quantum Electron.2, 311-318 (1996)) or multiple wave plates (Zhang Lu, Hu Qianggao , Xu Yuanzhong, Liu Wen, Luo Yong, Xiao Yuan. Optical time-domain depolarizer: Chinese patent, 200420057805.1.2006-03-22), using electro-optic effect or mechanical rotation method to achieve scrambling of polarized light, but to different degrees There are shortcomings such as slow response speed

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