Potassium Dihydrogen Phosphate (KDP) and Potassium Dideuterium Phosphate (DKDP or KD*P) Potassium Dihydrogen Phosphate (KDP) and Potassium Dideuterium Phosphate (KD*P ) are among the most widely-used commercial NLO materials, characterized by good UV transmission, high damage threshold, and high birefringence, though their NLO coefficients are relatively low. They are usually used for doubling, tripling and quadrupling of a Nd:YAG laser at the room temperature. In addition, they are also excellent electro-optic crystals with high electro-optic coefficients, widely used as electro-optical modulators, such as Q-switches, Pockels Cells, etc. SGoptics’s KDP & KD*P products SGopticssupplies high quality KDP and KD*P crystals in large quantities for these applications. Because their polished surfaces are easier to be moistened, however, the user is advised to provide a dry condition (<50%) and the sealed housing for preservation. For this purpose, SGoptics also provides polishing and sealed housing services for the KDP family crystals. Our engineers will serve you to select and design the best crystal, according to the laser parameters you provide.