Integrated-optic Mach-Zehnder modulator with linearized modulation characteristic

Theoretical and experimental results are presented on the characteristics of a Mach-Zehnder integrated-optic modulator with TM- and TE-polarized waves simultaneously excited at its input. It is established that under certain conditions the modulator linearity for a wave combination can be substantially increased above that obtained when light of one polarization is used. In the experiments, adjustment of light polarization at the modulator input with respect to the crystal axis ensured an optimal ratio of the wave intensities, so an increase of the linearity range (LR) from 69% to 92% was achieved and the dynamic range (DR) was improved from 75 dB to 87 dB.