Light source phase noise test method and light source phase noise test device

Abstract

The invention discloses a light source phase noise test method and a light source phase noise test device. The method comprises steps: firstly, a phase modulator is arranged on one way of delay fiber of a fiber interferometer, and modulation signals are loaded in the phase modulator; then, light source signals are transmitted to the fiber interferometer along the fiber, and interference signals generated by the fiber interferometer are modulated through the modulation signals; and finally, a phase generated carrier demodulation method or a working-point control method is used for demodulating the modulated interference signals, phase noise signals of the light source are acquired, and measurement on the light source phase noise is realized. through arranging the phase modulator on one way of delay fiber of the fiber interferometer, the fiber interferometer with a short-range difference is delicately used, phase modulation and interference signal acquisition are carried out synchronously, the phase noise is calculated according to an interfering modulation waveform through a demodulation algorithm, direct measurement on the light source phase noise is completed, a high-frequency detector and a high-frequency acquisition system are not needed, the system structure is greatly simplified, and the product price is reduced.

Description

technical field [0001] The invention belongs to the field of optical fiber technology, in particular to a method and device for testing the phase noise of a light source. Background technique [0002] In laser radar, coherent optical-optical communication, and coherent detection fiber optic sensing systems, the phase noise of the light source is a key technical indicator that affects system performance. The lower the linewidth of the light source, the lower the phase noise of the light source, so the phase noise of the laser is generally characterized by measuring the linewidth of the laser. [0003] The measurement methods of light source line width mainly include optical heterodyne method and fiber delay self-heterodyne method. Optical heterodyne method uses a stable standard light source to perform heterodyne with the measured light source. High and hardly practical. The fiber-delayed self-heterodyne method divides the output light of the light source into two beams. Af...

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Problems solved by technology

[0005] The invention provides a method and device for testing the phase noise of a light source, the purpose of which is to overcome the problem that the phase noise of a light source cannot be directly measured in the prior art

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