Growth of Twin-Free AgGaS 2 Single Crystals by a Self-Seeding Vertical Gradient Freezing Method and Difference Frequency Generation Using These Crystals

• Published in: Japanese Journal of Applied Physics Vol. 39; no. S1; p. 46
• Main Authors: Niwa, Eiji, Haidar, Sajjad, Masumoto, Katashi, Ito, Hiromasa
• Format: Journal Article
• Language: English
• Published: 01-01-2000
• ISSN: 0021-4922; 1347-4065
• DOI: 10.7567/JJAPS.39S1.46

We investigated different conditions for the growth of twin-free crystals of AgGaS
2
and then examined difference frequency generation (DFG) using the crystals to apply the new technology to coherent light sources tunable from 5 to 12µm. The number of lamellar twins in a crystal decreased with increasing growth rate and vanished at growth rates greater than or equal to about 1 mm/hour. Growth under these conditions allowed us to obtain the twin-free AgGaS
2
single crystals. Using these crystals, a DFG output of 5-12µm was obtained by angle tuning on phase matching angle ranges of 32-37° for type-I and 38-43° for type-II respectively. These phase-matching angles coincided with angles of the growth directions from the c-axis. It was found that longer optical crystals capable of producing difference frequency waves tunable from 5 to 12µm could be prepared from the AgGaS
2
single crystal boules grown by our VGF method, without suffering cutting losses.