Optical modulation using anti-crossing between paired amplitude and phase resonators

An optical modulator design based upon anti-crossing between coupled silicon microrings with independent amplitude and phase functionality is presented. The device exhibits over 25x improvement in sensitivity to an input drive signal when compared with previously studied microring modulators based on control of waveguide-resonator coupling. The new design also demonstrates an ON-OFF contrast of 14 dB, and has an ultra-compact footprint of 0.003 mm 2. The observed sensitivity enhancement suggests that this modulator may be driven directly by digital CMOS electrical signals with less than 1 V amplitude. © 2007 Optical Society of America.