200-mW-Average Power Ultraviolet Generation at 0.193 (mu)m in K2Al2B2O7

K2Al2B2O7 has been found to be phase matchable for type-1 sum-frequency generation (SFG) at 0.193 (mu)m by mixing the Nd:YAG laser wavelength at 1.0642 (mu)m and the SFG output of the RbTiOAsO4 optical parametric oscillator tuned at 0.2358 (mu)m. An average power of 200 mW at 10 kHz was obtained in a 7-mmlong crystal. In addition, the Sellmeier equations and the thermo-optic dispersion formula, which predict well the phase-matching conditions and temperature phase-matching bandwidths (FWHM) for second-harmonic generation and SFG in the 0.193-0.669-(mu)m range, are presented.