Potassium titanyl phosphate: properties and new applications

Potassium titanyl phosphate (KTP) is a unique nonlinear-optical material that is being widely used for second-harmonic generation of Nd lasers emitting near 1 μm. KTP is also attractive for various sum- and difference-frequency and optical parametric applications over its entire transparency range from 0.35 to 4.5 μm. Its combination of large electro-optic coefficients and low dielectric constants makes KTP potentially useful for various electro-optic applications, and, in particular, it has a figure of merit for an optical waveguide modulator that is nearly a factor of 2 larger than that for any other inorganic material. Low-loss optical waveguides can be formed in KTP, and several electro-optic and nonlinear-optic devices have been fabricated that confirm that KTP is also a superior material for many optical waveguide applications.