Tunable narrow-linewidth fiber laser based on interval tunable phase shift fiber gratings

Abstract

The invention relates to a tunable narrow-linewidth fiber laser based on an interval tunable phase shift fiber gratings. The tunable narrow-linewidth fiber laser based on the interval tunable phase shift fiber gratings comprises a laser device (LD), a WDM coupler, an erbium-doped fiber loop, an optical isolator, a circulator, the fiber gratings, a phrase shift fiber grating tuner, an optical coupler, a wavelength meter, an input and control circuit and an output optical coupler, wherein the WDM coupler, an erbium-doped fiber, the optical isolator, the circulator, the phrase shift fiber grating tuner and the optical coupler form an loop cavity; the circulator, the fiber gratings and the phrase shift fiber grating tuner form an adjustable filter inside the cavity. Phase shift amount of the phrase shift fiber gratings is changed by changing the length of an air gap between the two fiber gratings so that tuning of output laser wavelength can be achieved. According to the tunable narrow-linewidth fiber laser based on the interval tunable phase shift fiber gratings, the tunable phase shift fiber gratings, the optical coupler, the wavelength meter, the input and control circuit and the output optical coupler form an input and feedback control loop, the needed laser wavelength is obtained through feedback control, and stability of the laser output wavelength is ensured.

Description

technical field [0001] The invention relates to the technical field of fiber lasers, in particular to a tunable narrow-linewidth fiber laser based on a gap-tunable phase-shifting fiber grating. Background technique [0002] Fiber lasers are developed on the basis of fiber amplifier technology. As a new type of light source, it has unique advantages: flexible optical fiber output, can work in harsh environments, compact structure, high energy density, strong anti-electromagnetic interference, high conversion efficiency, tunable and so on. It has broad application prospects in the fields of optical fiber communication, optical fiber sensing, military, industrial processing, optical information processing and full-color display. In particular, tunable fiber lasers play an extremely important role in wavelength division multiplexing fiber optic communication and fiber optic sensing applications. [0003] Fiber Bragg grating is an optical passive device produced by using the ph...

AI Technical Summary

Problems solved by technology

Among them, mechanical tuning and electromagnetic tuning are simple and easy, but due to the limitation of the strain characteristics of the fiber grating itself, it is difficult to obtain a large tuning range

However, thermal tuning also has problems such as slow tuning speed, low precision, and thermal hysteresis.

In addition, the current tunable fiber lasers also have problems in the stability of the output wavelength, mainly because factors such as temperature and strain will affect the wavelength of the output laser, thus limiting the accuracy and stability of the fiber laser

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