Laser phase noise measurement method and system

Abstract

The invention relates to the technical field of laser testing, in particular to a laser phase noise measuring method and system. The system comprises a laser, a delay interference device and a spectrum analyzer, and further comprises a balanced photoelectric detector, the laser is used for generating a laser signal and transmitting the laser signal to the delay interference device, the delay interference device is used for obtaining two paths of phase noise optical signals through interference after receiving the laser signal, and the spectrum analyzer is used for analyzing the phase noise optical signals. The delay interference device transmits the obtained two paths of phase noise optical signals to the balance photoelectric detector, the balance photoelectric detector generates radio frequency signals according to the received two paths of phase noise optical signals and transmits the radio frequency signals to the spectrum analyzer, and the spectrum analyzer displays a measurement result according to the received radio frequency signals. According to the invention, the amplitude of the radio frequency signal output to the spectrum analyzer is very strong, the noise signal of the laser can be clearly observed on the spectrum analyzer, and a more accurate noise measurement result can be obtained.

Description

technical field [0001] The invention relates to the technical field of laser testing, in particular to a laser phase noise measurement method and system. Background technique [0002] Lasers used in coherent optical communications require very good noise characteristics. Coherent optical communication technology has two typical applications: 1) Data communication transmission, which is the main technical field of optoelectronics. Coherent refers to the extraction of signals at the receiving end of optical communication through coherent detection technology. If the noise of the laser used for coherent detection is smaller, the extracted signal will be clearer; or the original transmitted signal can be correctly extracted from the weaker signal received at the receiving end. 2) Laser ranging for autonomous driving. With the continuous development of automobile autonomous driving technology, higher requirements are put forward for the ranging accuracy and measurement range of ...

AI Technical Summary

Problems solved by technology

Disadvantages of this system: 1) Two scans are required for each measurement, the two outputs of Out 0 and Out 1 of DI are measured respectively and the average value is taken as the final result, the purpose is to eliminate the difference between the two outputs of Out 0 / 1 The "systematic error" caused by (as discussed later)

2) The amplitude of the radio frequency noise signal sent to the spectrum analyzer is very low, and it is not easy to observe

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