Optically linearized electrooptic light modulator using coated dielectric thin films

A scheme to extend the linearity of electrooptic light modulator using coated dielectric thin film is described. The simulation is based on a modulator configuring as a straight Ti: LiNbO₃ channel waveguide flanked by electrodes. Linearization is achieved through a reflection of light in both TE and TM modes at the edges of the modulator. The thickness and type of the film can be adjusted to obtain various values of reflectances. By changing the substrate temperature, the phase shifts experienced by TE and TM polarizations can be tuned. An improvement of spurious dynamic range (SFDR) for 7 dB is shown comparing to one seen in conventional interferometric type of modulators.