Pulsed blue light generation with KNbO3

KNbO3 yields very high non-linear coefficients. This material is attractive and widely used for the frequency doubling of cw and quasi cw near infrared laser sources. However it is not commonly used for pulsed applications. Frequency doubling of a pulsed high peak power titanium doped sapphire (Ti:S) laser with KNbO3 has been investigated. Close to 60 % conversion efficiencies have been obtained in external cavity single shot operation. Factors limiting the conversion efficiency in a repetitive mode and with longer crystals have been identified. Quadrature second harmonic generation technique has been shown to overcome some of these limitations compared to single crystal technique. First experimental results for frequency doubling the Nd:YAG and Nd:YAlO F-4(3/2)-I-4(9/2) laser transition in the pulsed nanosecond regime with KNbO3 are also presented below.