Measurements are described on asymmetric interferometric channel waveguide modulators in Ti:LiNbO
3at 0.83-μm wavelength. Modulation voltages and device transmissions are compared for

and

-cut substrates. An interferometer intrinsic phase bias of

allows linear modulation and we have observed linearity over 67 dB for a 3-kHz bandwidth. This dynamic range is limited by optical damage effects, of which the photovoltaic effect is the most critical.