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.