The present application provides an
ultraviolet laser, which includes, in order, a pump source, a collimating lens, a focusing lens, a first cavity mirror, a
gain medium, a Q-switching element, and a second cavity mirror in the first direction; a third cavity mirror and a displacement motor in the second direction; a first
spectrometer, a frequency-doubling
crystal, and a fourth cavity mirror in the third direction; a fifth cavity mirror in the fourth direction; and a second focusing lens 23, a second frequency-doubling
crystal 25, a second collimating lens 26, a sixth cavity mirror 27, and a second
spectrometer 28 in the fifth direction. The present application achieves adjustable cavity length by moving the displacement motor to drive the third cavity mirror in the second direction, thereby enabling the
ultraviolet laser to obtain a cavity length adapted to the corresponding
power output at different output powers. Consequently, a highly integrated
ultraviolet laser with precisely adjustable cavity length, compatible with multiple high- and low-power overlapping stable outputs, and a compact structure is obtained.