Efficiency Improvement of Electro-optical Modulator on Thin Film Lithium Niobate with Offaxis Waveguide orientation

The modulation efficiency of electro-optical modulator (EOM) on thin film lithium niobate (TFLN) with arbitrary waveguide orientation with respect to the crystal axes is calculated theoretically and numerically. Compared with the conventional Y-propagation phase shifter direction on X-cut substrate, modulation efficiency can be further improved when rotating the phase shifters by certain angles within the Y-Z plane. Improvements of about 20-40% are achieved in simulation with three typical TFLN waveguide-electrode configurations.