The invention discloses a
femtosecond ultraviolet laser. The
femtosecond ultraviolet laser is composed of an optically connected seed source, a pulse broadener, an
optical amplifier, a
pulse compression module and a third frequency multiplication module. The seed source is an all-
fiber passive mode-locked seed source or a
solid mode-locked seed source; The pulse broadener is an all-
optical fiber broadener or a spatial light broadener; The
optical amplifier is an optically connected multi-stage
optical amplifier; The
pulse compression module is a
prism pair or a
grating pair or a chirped volumeBragg
grating (CVBG); The frequency tripling module sequentially comprises a 1 / 2 wave plate, a polarization
beam splitting prism, a convex lens, a concave lens, a frequency doubling
crystal, a frequency tripling
crystal, an absorbing block and an
ultraviolet window plate. The
second harmonic generation crystal is a kind of phase-matched
lithium triborate (LBO) crystal, and the
third harmonic generation crystal is a kind of phase-matched
lithium triborate (LBO) crystal. The back surface of the
third harmonic generation crystal is not coated and cuts the Brewster angle Theta B 1 of ultravioletlight, and the front surface of the
second harmonic generation crystal is not coated and cuts the Brewster angle Theta B 2 of
infrared light. The
femtosecond ultraviolet
laser realized according to the invention has simple and stable structure, long service life and is suitable for generating high-power femtosecond
ultraviolet light.