Method and apparatus for generating differential quadrature phase shifting keying code optical signal

Abstract

The invention discloses a method and a device for producing a differential quadrature phase-shift keying code optical signal, which belong to the field of communication. The method comprises the steps of: performing light-splitting processing on an optical signal to obtain two polarized light signals; performing modulation and phase-shift processing on one of the polarized light signals to obtaina polarized light signal after the phase shift, and modulating the other polarized light signal to obtain another polarized modulated light signal; performing light combination processing on the polarized light signal after the phase shift and another polarized modulated light signal to obtain a polarization-multiplexed optical signal; and performing polarization processing on the polarization-multiplexed optical signal to obtain the differential quadrature phase-shift keying code optical signal. The device comprises a polarization light splitter, a modulator, a phase-shift controller, a polarization light combiner and a polarizer. The method and the device can steadily produce the differential quadrature phase-shift keying code optical signal through light-splitting processing, modulation and phase-shift processing, light combination processing and polarization processing.

Description

technical field [0001] The invention relates to the communication field, in particular to a method and a device for generating a differential quadrature phase-shift keying code optical signal. Background technique [0002] The increase of video services in the network imposes higher requirements on the capacity of the entire network. Therefore, it is now required to upgrade the rate of the optical network, and the rate of the next-generation optical network is 40Gb / s and higher. For example, the rate of Ethernet is upgraded at a speed of 10 times, and 100GE is currently under discussion, and 100Gb / s optical transmission technology has become a hot issue today. [0003] For the 40Gb / s optical transmission system, there are various optical modulation code types, such as NRZ (Non-Return-to-Zero, non-return-to-zero) code, RZ (Return-to-Zero, return-to-zero) code, CSRZ (Carrier Suppressed Return-to-Zero (carrier suppression return to zero) code, ODB (Optical Duobinary, optical ...

AI Technical Summary

Problems solved by technology

[0006] The main disadvantages of this solution are: First, the Y branch splitter has a very important impact on the entire device

The Y-branch optical splitter needs to split the optical signal into two optical signals with the same optical intensity, which is complicated and expensive to implement.

Second, it is difficult to control the light intensity percentages of the X polarization component and the Y polarization component of the two-way light, which will lead to instability of light intensity, thereby deteriorating the transmission performance, and due to changes in external factors (such as temperature, vibration) will result in a change in the percentage of the polarization component

[0008] The main disadvantages of this scheme are: the phase modulator needs a very high frequency response, for example, in the 40G GB / s DQPSK system, the phase modulator is required to ensure 90-degree phase modulation at 20G In the / s DQPSK system, the phase modulator is required to ensure 90-degree phase modulation at 50G baud rate, but this is difficult to achieve

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