Generation of the fifth harmonic of picosecond yttrium aluminate laser radiation

An investigation was made of the generation of the fifth harmonic of the radiation emitted by a picosecond Nd³⁺-activated yttrium aluminate laser. The harmonic was generated by three different methods using KDP and potassium pentaborate crystals. An optimal method was developed for generating the fifth harmonic (λ = 216 nm) with an output energy of 0.5 mJ in the form of pulses of 15-ps duration.