Optical coherent receiver time delay and phase difference test method and test system

Abstract

The invention discloses an optical coherent receiver time delay and phase difference test method which comprises the following steps: generating beat frequency through inputting scanning signals, of which the frequency is similar to that of local oscillator signals, to an optical coherent receiver to be tested; collecting beat frequency information output by each radio frequency of the optical coherent receiver to be tested by utilizing an oscilloscope; carrying out noise elimination through the FFT operation and calculating the phase and frequency of the beat frequency; and finally, carrying out linear fitting to obtain relation curve of the phase and frequency, and calculating the time delay and phase difference between channels of the optical coherent receiver to be tested according to the curve. The invention also discloses a test system for the method. The test system comprises a local oscillator signal source, a tunable scanning signal source, the optical coherent receiver to be tested, the oscilloscope and a data processing unit. The beat frequency method is utilized to test the time delay and phase difference between the channels of the optical coherent receiver to be tested, so that simple and practicable effects are achieved, time delay and phase difference between the channels can be accurately measured, the difficulty that a conventional instrument cannot directly measure the phase difference and time delay between 25 GHz high-speed signal channels is overcome, and the repeatability of test data is good.

Description

technical field [0001] The invention relates to the field of optical communication, in particular to a method and system for testing time delay and phase difference of an optical coherent receiver. Background technique [0002] The development of communication technology has greatly promoted the progress of human society. From the second half of the 20th century to the present, optical fiber communication technology has developed rapidly at an unprecedented speed. With the development of the Internet, various emerging network traffic services have sprung up, including web page data, e-mail, online games, online videos, etc. The emergence and growth of these services have put forward new requirements for the capacity of communication systems. [0003] At the receiving end, the optical receiver receives and demodulates the optical signal modulated at the transmitting end. After long-distance transmission, there is often a delay difference between channels after receiving and ...

AI Technical Summary

Problems solved by technology

After long-distance transmission, there is often a time delay difference between channels after the optical receiver receives and demodulates, making the demodulation incomplete, so that high-performance receiving and demodulating cannot be obtained

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