Electro-optic phase modulation in ridge waveguides of epitaxial K(0.95)Na(0.05)Ta(0.71)Nb(0.29)O(3) thin films.

Electro-optic modulation at lambda=1.5 mum has been demonstrated for the first time to the best of our knowledge in a ridge waveguide phase modulator produced in cubic potassium sodium tantalate niobate thin films epitaxially grown on potassium tantalate substrates exploiting the large quadratic electro-optic Kerr coefficient of R11 = 8.2x10(-17) m(2)/V(2). The relative permittivity, Kerr coefficient, and refractive index have been evaluated for the thin film crystal and are compared to the values measured in bulk crystals. The half-wave voltage times length figure of merit of the modulator has been measured to be Vpil=38 Vcm at room temperature.