A tunable ultraviolet laser source in the spectrum range of 0.36-0.388 μm was obtained as second harmonics from a
frequency doubled Alexandrite laser whose output covers the wave range over 0.72-0.78 μm. A LBO crystal was used as
frequency doubling crystal. The phase mateching angle in the wide spectrum range of the crystal was calculated, and the
crystal was cut in the way that the normal incidence at the center wavelength of the fundamental wave at the crystal. The
output spectrum line was measured and the highest second harmonics conversion efficiency reached 1.2% from long
pulse fundamental wave at the center wavelength.