Ultra-wideband digital laser phase-locked loop device and phase locking method

Abstract

The invention discloses an ultra-wideband digital laser phase-locked loop device, comprising an optical mixer, a balanced detector, a first AD sampling circuit and a second AD sampling circuit, and a phase fine tracking loop and a phase coarse tracking loop, wherein the optical mixer is used for mixing a received optical signal with a local oscillation signal to obtain four paths of mixing signals; the balanced detector is used for converting the four paths of mixing signals into a first path of electric signals and a second path of electric signals that are orthogonal to each other; the first AD sampling circuit and the second AD sampling circuit are separately used for sampling the first path of electric signals and the second path of electric signals according to a preset sampling frequency to obtain a corresponding first digital signal and a corresponding second digital signal; and a phase fine tracking calculation module and a phase coarse tracking calculation module are achieved through an FPGA chip. According to the ultra-wideband digital laser phase-locked loop device disclosed by the invention, an effective compensation can be achieved in the case of a large frequency difference between the received optical signal and the local oscillation signal, and the communication reliability can be improved. The invention also discloses an ultra-wideband digital laser phase locking method.

Description

technical field [0001] The invention relates to the technical field of optical communication, in particular to an ultra-wideband digital laser phase-locked loop device and an ultra-wideband digital laser phase-locked method. Background technique [0002] The purpose of communication is to transmit information quickly, efficiently, safely and accurately through channels. As an important part of the future information highway, satellite communication technology has become an important force to promote social progress and improve human living standards. [0003] With the deepening of research on inter-satellite communication, people's requirements for data rates have been developed towards several Gbps. Therefore, the coherent optical communication system using laser as the information carrier has entered people's sight, and it has become an inevitable trend in the development of satellite communication to replace microwave links with laser links. [0004] Laser has the chara...

AI Technical Summary

Problems solved by technology

There are two main methods of optical phase-locked loop, one is the analog phase-locked loop circuit, the other is the digital phase-locked loop circuit, although the digital optical phase-locked loop circuit has a simple and flexible structure, superior performance, and good scalability, but due to the The Doppler frequency shift of the received optical signal and the local optical signal in the communication system is greater than + / -7GHz. At the same time, the small drift of the laser may cause the frequency difference between the signal light and the local oscillator frequency to become very large, which may reach several On the order of tens of GHz

[0008] When implementing the present invention, the inventor found that the digital optical phase-locked loop using a single loop in the prior art cannot directly compensate such a large frequency difference

Images