Active Q-switched distributed feedback fiber laser

Abstract

The invention relates to an active Q-switched distributed feedback fiber laser, which is characterized in that a single-mode semiconductor pump laser is connected with a pump end of a wavelength division multiplexer, an optical fiber isolator is connected with a signal end of the wavelength division multiplexer, and an active phase shift fiber grating is connected with a common end of the wavelength division multiplexer, so that the distributed feedback fiber laser is formed; and the active phase shift fiber grating is fixed on an active phase shift fiber grating fixing device, a pressure device periodically extrudes a phase shift point of the active phase shift fiber grating under the control of a driver, and the effective phase shift amount of the fiber grating is changed, so that a threshold value of the laser is changed, and the active Q-switched laser process is realized. The active Q-switched distributed feedback fiber laser has the beneficial effects that the performance advantages of the distributed feedback fiber laser are fully utilized, a device for modulating the laser cavity Q by changing the grating phase shift amount is simply added, the pulse emission control of laser is realized, and the purposes of narrow linewidth and pulse work are achieved.

Description

technical field [0001] The invention relates to the technical field of fiber lasers, in particular to an active Q-switching distributed feedback fiber laser. Background technique [0002] In application technologies such as distributed optical fiber sensing and lidar, in order to simultaneously obtain measurement and event location information, the light source is often required to have narrow linewidth and short pulse performance. At present, the commonly used technical method is to switch and chop the narrow linewidth light source operated by continuous wave, such as modulation by acousto-optic modulator or electro-optic modulator to generate laser pulse. But this increases the complexity and cost of the system on the one hand, and reduces the utilization rate of laser energy on the other hand. [0003] Pulsed fiber lasers mainly use mode-locking and Q-switching schemes, while Q-switched fiber lasers generally use active Q-switching with Q-switching devices inserted in th...

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Problems solved by technology

But on the one hand, this increases the complexity and cost of the system, on the other hand, this method reduces the utilization rate of laser energy

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