Extremely high damage threshold of a new nonlinear crystal L-arginine phosphate and its deuterium compound

L‐arginine phosphate monohydrate (LAP) and deuterated LAP (DLAP) are new organic nonlinear optical materials useful for higher harmonics of radiation from high‐power lasers. We measured the bulk laser damage threshold of these crystals using light from a 1.05 μm laser with 1 and 25 ns pulse widths and 0.53 μm laser light with 0.6 and 20 ns pulse widths. In every case, these crystals show much higher thresholds than potassium dihydrogen phosphate (KDP and fused silica. These crystals are very interesting not only as a frequency converter but also as other optical components of high‐power lasers, because of their extremely high damage threshold.