Linear interferometric modulators in Ti:LiNbO3

Measurements are described on asymmetric interferometric channel waveguide modulators in Ti:LiNbO
3
at 0.83-μm wavelength. Modulation voltages and device transmissions are compared for
X-, Y-
and
Z
-cut substrates. An interferometer intrinsic phase bias of
\sim\pi/2
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.