Method and device for producing quadrature amplitude modulation signal light

Abstract

The invention belongs to the optical communication technology, and discloses a method and a device for producing a quadrature amplitude modulation signal light. The method comprises the following steps of: regulating a polarization state of an input signal light so as to project the signal light into two polarized and orthogonal signal lights on a fast axis and a slow axis of a tunable differential group time delay unit; introducing a group time delay difference between the two polarized and orthogonal signal lights; then, projecting the two polarized and orthogonal signal lights along a light-transmitting direction on a polarization analyzer after executing polarization control; and obtaining the corresponding quadrature amplitude modulation signal light by performing the related vector addition on the two projected signal lights in the light-transmitting direction, wherein the two projected signal lights are in the same polarization direction. The device comprises a first polarization controller, a first tunable differential group time delay unit, a second polarization controller and a first polarization analyzer, which are orderly connected. When the QPSK signal light is input, the 16-QAM signal light is output; and when the 16-QAM signal light is input, the 256-QAM signal light is output. The method and the device are simple and easy to implement, and the components used are all passive devices, can work under high speed condition and simultaneously have excellent expandability.

Description

technical field [0001] The invention belongs to the optical communication technology, relates to the generation of advanced modulation format signal light, in particular to a method and device for generating signal light of quadrature amplitude modulation (16-QAM and 256-QAM). Background technique [0002] In recent years, the emergence of advanced advanced modulation formats has effectively promoted the rapid development of high-speed and large-capacity optical communication networks. The combination of advanced advanced modulation formats and coherent detection has become an important trend in the development of optical communication. Compared with traditional binary modulation formats (1 bit / symbol) such as on-off keying (OOK) and differential phase-shift keying (DPSK), advanced modulation formats use multi-ary, that is, multiple bits are included in one symbol Information, so it can effectively improve the information rate, communication capacity and spectral efficiency....

AI Technical Summary

Problems solved by technology

[0003] The traditional method and device for generating QAM is to use cascaded in-phase / quadrature modulators (I / Q modulators) or a single I / Q modulator and multi-level electrical signals. Although it has been widely used, it is more complicated to implement , the more multi-level QAM is more difficult to implement, and the QAM performance degradation is more serious

At the same time, the symbol rate is relatively limited, and it is difficult to generate high-speed multi-level QAM

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