The application provides a tunable pulse
train laser and a design method thereof, the
laser comprising a pumping light
fiber coupling focusing
system, a cavity mirror, a
laser crystal, a passive Q-switching
crystal, an active Q-switching
system and a laser output mirror arranged in sequence according to an
optical path; the tunable pulse
train laser is configured to: in a working state, through the equivalent length control of the passive Q-switching
crystal and the modulation control of the active Q-switching
system, the number of pulse trains is controlled under the same main frequency, or the same pulse
train is output under different main frequencies. The application uses the active Q-switching system and the passive Q-switching crystal in cooperation, uses the active Q-switching and the passive Q-switching in combination to obtain the output of the main frequency plus the pulse train, is favorable for the multiple
processing at the same point in the fine
machining, and the
single pulse energy is constant, thereby providing a pulse train laser scheme which is lower in cost, more ingenious and simple in structure, good in regulation flexibility, and higher in stability and reliability of the laser.