title: Low-energy MOS depletion modulators in silicon-on-insulator micro-donut resonators coupled to bus waveguides.
abstract: Electrical, optical and electro-optical simulations are presented for a waveguided, resonant, bus-coupled, p-doped Si micro-donut MOS depletion modulator operating at the 1.55 μm wavelength. To minimize the switching voltage and energy, a high-K dielectric film of HfO₂ or ZrO₂ is chosen as the gate dielectric, while a narrow ring-shaped layer of p-doped poly-silicon is selected for the gate electrode, rather than metal, to minimize plasmonic loss loading of the fundamental TE mode. In a 6-μm-diam high-Q resonator, an infrared intensity extinction ratio of 6 dB is predicted for a modulation voltage of 2 V and a switching energy of 4 fJ/bit. A speed-of-response around 1 ps is anticipated. For a modulator scaled to operate at 1.3 μm, the estimated switching energy is 2.5 fJ/bit.
authors.affiliation: Department of Physics, University of Massachusetts at Boston, Boston, Massachusetts 02125, USA. soref@rcn.com
authors.forename: Richard
authors.initials: R
authors.lastname: Soref
authors.forename: Junpeng
authors.initials: J
authors.lastname: Guo
authors.forename: Greg
authors.initials: G
authors.lastname: Sun