Optical waveguide Fabry–Perot modulators in LiNbO 3

Fabry–Perot-type electro-optic modulators have been produced with Ti:LiNbO3 optical waveguides. The end mirrors are formed by depositing six pairs of SiO2 and TiO2 layers at the waveguide input and output faces. A Vπ of approximately 4 V was measured at 0.81 μm wavelength for the extraordinary polarization in a 7-mm interaction length. Comparison of the modulation performance in the linear region with the modulation performance of a polarization intensity modulator of similar geometry indicates a sensitivity for the Fabry–Perot modulator that is ∼3 times larger. The sensitivity can be further improved by using higher reflectance mirrors and reducing waveguide losses.