KTP Potassium titanyl phosphate (KTiOPO4) crystal 2.7 x 3 x 2.2 mm made by Cristal Laser SA for Melles Griot. These were used for second harmonic generation (SHG) commonly called frequency doubling, converting 1064nm laser light to 532nm in a DPSS laser system. These are new crystals in factory packaging.
