Efficient second harmonic generation of near-infrared laser light (λ = 840-950 nm) can be performed with a KNbO3 crystal due to its large nonlinear optical coefficient d32 = 21 pm/V and the possibility of noncritical 90° phase matching for the wavelength λ = (860 ± 1) nm at room temperature. In the orthorhombic phase (T=−50–223°C) of KNbO3 (point group symmetry mm2) the phasematching wavelength can be temperature tuned between λ = 838 nm (T =−36°C) and λ = 950 nm (T = +180°C).

© 1984 Optical Society of America

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