Abstract

Tunable cw ultraviolet radiation was generated by sum frequency mixing of the radiation from a DFB-type laser diode with the radiation from an argon-ion laser in a nonlinear crystal of β-BaB₂O₄. The wave-lengths of the radiation generated by sum frequency mixing, of the argon-ion laser, and of the laser diode were ~370, 514.5, and 1310 nm, respectively. The crystal was cut to a length of 7 mm and θ = 29° for type-I phase matching and was held at 40 ± 1 °C to prevent surface degradation due to atmospheric water vapor. The phase matching was made by angular tuning. A preliminary result of several nanowatts of radiation at ~370 nm was obtained by the radiation of 3.2 mW from the laser diode and the radiation of 500 mW from the argon-ion laser. The generated power could be increased by improving the collimation and optimizing the focusing of the laser diode. The dependence of the input radiation power and tolerances of the crystal tuning angle and wavelength of the laser diode were measured.

© 1989 Optical Society of America