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Photochromic damage in nonlinear crystals for high-peak power blue light generation

This paper investigates picosecond blue-light induced infrared absorption in bulk ferroelectric nonlinear crystals KTiOPO4 (KTP), RbTiOPO4 (RTP), congruent MgO:LiNbO3 (MgO:CLN), KNbO3 as well as recently developed Rb:KTP, Ce:KTP, stoichiometric LiTaO3 (SLT), MgO:SLT and stoichiometric MgO:LiNbO3, (MgO:SLN). These ferroelectrics are characterized by high nonlinearities and have been proven suitable for fabricating periodically poled structured for quasi-phase matched second harmonic generation in the blue spectral region. Because poling can introduce additional defects and modify susceptibility to the photochromic damage, periodically poled structures of selected ferroelectrics have been separately investigated. In addition, the BLIIRA was measured in BiB3O6 (BiBO) the most promising birefringence phase-matched crystal for pulsed blue light generation to emerge in recent years.