Laser line width measuring system and method based on electro-optic modulator and adjustable radio source

Abstract

The invention discloses a laser line width measuring system and method based on an electro-optic modulator and an adjustable radio source. The system comprises a to-be-measured laser, an opto-isolator, a 2*2 optical fiber coupler, an integrated photoelectric detector, a spectrum analyzer and a frequency shift fiber ring. The frequency shift fiber ring is connected between an output port D and an input port C of the 2*2 optical fiber coupler and at least comprises a frequency shifting device and an optical fiber delay line, wherein the frequency shifting device is composed of the electro-optic modulator and the adjustable radio source. The adjustable radio source is used for providing radio driving signals with the adjustable frequency shifting amount for the electro-optic modulator, and the frequency shifting amount can be adjusted in real time by controlling the modulation frequency injected into the electro-optic modulator by the adjustable radio source. The frequency shifting amount can be increased, the adjustable band width range is enlarged to 10 GHz, and the line width measurement limit reaches 1 Hz.

Description

technical field [0001] The invention relates to the field of line width measurement of narrow line width lasers, in particular to a laser line width measurement system and method based on an electro-optical modulator and an adjustable radio frequency source. Background technique [0002] In recent years, narrow linewidth lasers (kHz and below the kHz order) have been widely used in optical fiber communication, optical fiber sensing and optical precision measurement and other fields. With the maturity and development of the optical communication industry, the cost of a large number of high-performance lasers has been continuously reduced, especially semiconductor lasers, whose output power and linewidth characteristics have been greatly improved. Therefore, it is particularly important to accurately measure the laser linewidth to evaluate the performance of a laser. The existing laser linewidth measurement methods can be divided into two categories: instrument measurement me...

AI Technical Summary

Problems solved by technology

In the previous research process, we found that the frequency shift part of the traditional loss self-compensation cycle delay self-heterodyne method uses an acousto-optic modulator, and its frequency shift range is only on the order of megahertz, and the frequency adjustable range is small

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