Generation of ultraviolet radiation with wide angular tolerance in cesium lithium borate crystal

GOPAL C BHAR, PATHIK KUMBHAKAR* and ANIL K CHAUDHARY

Laser Laboratory, Physics Department, Burdwan University, Burdwan 713 104, India

* Present address: Regional Engineering College, Durgapur 713 209, Burdwan, India

Email: buphygcb@dte.vsnl.net

Abstract.

Tangential phase-matching has been realised in cesium lithium borate (CLBO) crystal for the first time for the generation of fourth harmonic (266 nm) of Nd:YAG and third harmonic (226.7 nm) of a dye laser radiation by second harmonic generation and sum-frequency mixing with the angular tolerance as large as 22 mrad and 21 mrad respectively, over one of the interacting beams. An energy conversion efficiency of 15% for fourth harmonic generation is obtained with a 5.5 mm thick crystal and with the average pump powers only 170 and 70 mW. A set of Sellmeier dispersion equations for the CLBO crystal have also been formulated.

Keywords: Non-linear optics; ultraviolet radiation; tangential phase-matching; Sellmeier dispersion.

Pacs No. 42.65.Ky; 86.70L; 42.70Nq