Low Temperature Hydrothermal Growth of KTiOPO sub 4 (KTP).

KTP possesses superior properties as a phase matched nonlinear optic material. It is not hygroscopic, has a large effective nonlinear coefficient, excellent optical damage, resistance, small beam walk-off angle, and large thermal and angular bandwidths. These combined factors have dictated its choice as a second harmonic generator when compared to previous materials. Ba sub 2 NaNb sub 5 O sub (15) is difficult to grow, KH sub 2 PO sub 4 is hygroscopic, LiIO sub 3 has small spectral bandwidth, and LiNbO sub 3 suffers optical damage easily. Even the recently emphasized Beta-BaB sub 2 O sub 4 has a larger walk-off angle, smaller angular acceptance, and a smaller d-coefficient. In addition, the larger acceptance angle for KTP results in higher output for miniature configurations at low power input. KTP has lately found new applications for optical waveguiding, sum frequency mixing, and parametric oscillators.