ULTRAVIOLET GENERATION AT 266 NM IN A NOVEL ORGANIC NONLINEAR-OPTICAL CRYSTAL - L-PYRROLIDONE-2-CARBOXYLIC ACID

A novel organic nonlinear optical crystal, L-pyrrolidone-2-carboxylic acid (L-PCA), has been found to be phase matchable for second-harmonic generation (SHG) and sum-frequency mixing down to the UV range at room temperature. Tunable radiation down to 266 nm was obtained. The nonlinear coefficient d14 Of L-PCA for the fundamental wavelength of 532 nm was determined to be 0.32 pm/V. The angular acceptance (the full width at half-maximum) of the type II phase-matched SHG has also been measured to be 3.03 mrad cm which agreed with the calculated value. This value is much larger than that of the type I phase-matched SHG in beta-BBO.