Pulse pump type standing wave resonant cavity nanosecond pulse laser

Abstract

The invention discloses a pulse pump type standing wave resonant cavity nanosecond pulse laser which comprises a pulse modulation circuit, a pump laser, a beam combiner, a gain fiber, an isolator and an output coupler; a doped fiber in a resonant cavity not only can play a role in gaining a medium under the pulse pump condition, but also can be taken as a saturable switch for quick response to generate a laser pulse of which the time domain width is within the nanosecond order of magnitude; the repetition frequency of the pulse depends on that of pump light; and the pulse width depends on the combined action of energy in the cavity and the length of the resonant cavity. The pulse pump type standing wave resonant cavity nanosecond pulse laser has the advantages of simple structure, tunable pulse width, tunable repetition frequency, high optical to optical conversion efficiency and the like, has good stability and is suitable for various application occasions for industrial processing.

Description

[Technical Field] [0001] The invention relates to the field of lasers, in particular to a pulse pumped standing wave resonator nanosecond pulse laser. [Background technique] [0002] With the widespread use of laser cutting, laser engraving, laser marking, laser scribing and other technologies in the fields of clothing, electronics, microprocessing, etc., the demand for nanosecond pulses with high stability, pulse width and repetition frequency tunable is also increasing. More urgent. At present, the commonly used methods for generating nanosecond pulses in the industrial processing field mainly fall into two categories: acousto-optic Q-switching technology and direct modulation and fast response semiconductor seed source technology. [0003] Acousto-optic Q-switching technology actually adds two coupling fibers on the basis of the bulk acousto-optic Q-switch. Due to the technology level of coupling the pigtail and the acousto-optic Q crystal, the insertion loss of the entire Q sw...

AI Technical Summary

Problems solved by technology

The laser pulse width output by the acousto-optic Q-switched laser is about 100-300ns. Moreover, the acousto-optic switch has poor switching capability for high-energy lasers, and its time-domain waveform has a long falling edge time and pulse asymmetry, which is limited by the switching time of the Q-switched crystal. limit, it is not possible to obtain nanosecond pulses with steep rising edges

[0004] The semiconductor seed source technology with direct modulation and fast response has a large repetition frequency tuning range, and the pulse waveform is easy to control. However, when working at a low repetition frequency, it is limited by the duty cycle and the average power is very small, only hundreds of microwatts. Generally, it needs Multi-level amplification can meet the needs of industrial processing

Moreover, the spectral width of the pulse directly output from the semiconductor seed source is only 0.2-0.4nm, such a narrow spectral width is very easy to stimulate various nonlinear effects in the subsequent multi-stage amplification process, such as SBS stimulated Brillouin scattering , Stimulated Raman scattering effect, etc., causing pulse spectrum distortion, time domain distortion, and even burning the gain fiber in severe cases

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