All-fiber pulsed fiber laser with composite chamber

Abstract

An all-fiber pulsed fiber laser device with a composite chamber comprises a semiconductor laser pumping source driven by a semiconductor laser pumping source driving module, a fiber wavelength division multiplexer, a gain medium fiber, a first optoisolator, a photo-coupler, a pigtailed photoswitch driven by a photoswitch driving module, and a second optoisolator, wherein an output terminal of the semiconductor laser pumping source is connected with a short wavelength input terminal of the fiber wavelength division multiplexer, an output terminal of the fiber wavelength division multiplexer is connected with an input terminal of the photo-coupler by successively passing through the gain medium fiber and the first optoisolator, an output terminal of the photo-coupler serves as an output terminal of the laser, one end of the pigtailed photoswitch is connected with a long wavelength input terminal of the fiber wavelength division multiplexer via the second optoisolator, a cascading interference chamber is arranged between the photo-coupler and the pigtailed photoswitch, an input terminal of the cascading interference chamber is connected with a feedback output terminal of the photo-coupler, and an output terminal of the cascading interference chamber is connected with the other end of the pigtailed photoswitch.

Description

technical field [0001] The invention relates to a composite cavity all-fiber pulse fiber laser system, which belongs to the technical field of rare earth doped fiber lasers. Background technique [0002] The fiber laser (Fiber Laser, FL for short) uses a rare earth-doped fiber as the gain medium, forms its laser energy level particle population inversion under the action of pump light, and combines the optical feedback of the resonator to form a laser oscillation output. Compared with other traditional solid-state and gas lasers, fiber lasers use gain medium fibers as energy storage units, and have the characteristics of compact structure, high conversion efficiency, good beam quality, wide output wavelength range, and strong environmental adaptability. , industry, military and medical and many other fields have been widely used, especially high-power, high-energy output pulsed fiber lasers based on Q-switching technology. The key to Q-switching technology is the high-speed...

AI Technical Summary

Problems solved by technology

[0003] The loss of the resonator generally includes reflection loss, absorption loss, diffraction loss, scattering loss, etc. Controlling different losses constitutes different Q-switching technologies. Currently, commonly used Q-switching methods include: saturable absorber Q-switching to control absorption loss, Its shortcomings are that the stability is poor, the generated pulse has a certain randomness, and the pulse width and repetition frequency cannot be adjusted; the acousto-optic Q-switching technology for controlling diffraction loss and the electro-optic Q-switching technology for controlling reflection loss, the latter two methods are passed in Acousto-optic switches or electro-optic crystals are built into the cavity to achieve Q value control. Although high repetition rate and narrow pulse width output can be achieved, the use of spatial optical path coupling causes excessive loss in the laser cavity and strict requirements for optical path alignment, which limits The output optical power is high, and the cost is very high. It is necessary to adopt a compact, low-loss all-fiber Q-switching technology to optimize the laser output efficiency and simplify the structure.

The linear cavity structure requires the optical fiber to strictly control the reflection coefficient of the fiber feedback end face or use the fiber grating as the reflection unit to realize the optical feedback. The technical requirements are complex and are easily affected by factors such as ambient temperature.

Since the pump light must enter the fiber through the cavity mirror at one end of the fiber, high pump power is easy to damage the cavity mirror film

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