Optical mixer of coherent reception machine

Abstract

The invention discloses an optical mixer of a coherent reception machine, and belongs to optical devices of optical fiber communication. The optical mixer of the coherent reception machine solves the problems that delayed differences exist among different output components of an existing optical mixer, and temperature stability is poor. The optical mixer of the coherent reception machine is provided with a wave separator, a 50 / 50 beam splitter, a phase shift piece, a wave combiner, a 1 / 2 wave piece and a polarization separator along the direction of an optical path in sequence. The optical mixer of the coherent reception machine serves as a 2*8 optical mixer, and uses characteristics of a single-axis birefringent crystal to achieve polarization separation, beam combination and optical process compensation. Light beams achieve phase shift of an angle of 90 degrees through the phase shift piece, and phase diversity control is achieved. Eight quartz crystals with different thicknesses of the polarization separator are used for compensating the delayed differences among different optical paths. Different devices are mature in machining technology, and good in temperature stability. The optical mixer of the coherent reception machine is compact in overall structure, high in polarization extinction ratio, and capable of being used for coherent demodulation of optical signals by using an advanced modulation format and a polarization multiplexing mode in the optical fiber communication.

Description

Technical field [0001] The invention belongs to an optical device for optical fiber communication, and in particular relates to a coherent receiver optical mixer, which is used to realize coherent reception and demodulation of optical signals transmitted in optical fibers using polarization multiplexing mode and advanced modulation format. Background technique [0002] In recent years, with the continuous upgrading of optical fiber communication systems, optical signals transmitted in optical fibers have begun to use advanced modulation formats and present the characteristics of carrying information in the entire field (amplitude, frequency, phase, and polarization). In view of this feature, a coherent detection method must be used at the receiving end of the system to obtain all the information carried by the optical signal. The Quadrature Phase Shift Keying (DP-QPSK) format using polarization multiplexing is a typical optical signal multiplexing and modulation method in the exi...

AI Technical Summary

Problems solved by technology

[0007] The invention provides a coherent receiver optical mixer, which solves the problems of delay difference and poor temperature stability between different output components of the existing optical mixer

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