5 mm thick periodically poled Rb-doped KTP for high energy optical parametric frequency conversion

A 5 mm thick periodically poled bulk Rb-doped KTiOPO sub(4) (KTP) crystal with a period of 38.86 mu m was fabricated by electric field poling. Chemical etching and optical evaluation show a high quality of the periodic ferroelectric domain structure through the whole crystal aperture. The fabricated quasi-phase matching (QPM) device was used in an optical parametric oscillator pumped at 1064 nm with 12 ns pulses at 100 Hz repetition rate to generate 60 ml parametric radiation with a conversion efficiency of 50%.