Thermo-optic tuning and switching in SOI waveguide Fabry-Perot microcavities

TLDR

The study discusses various device improvements. Tuning is achieved by passing current through the silicon cavity, enabling 2 nm thermo‑optic tuning with under 50 mW power. The demonstrated SOI waveguide microcavities achieve Q = 4,584, finesse 82, and enable fast switching with 1.9 µs rise time at <10 mW and 640 ns when overdriven.

Abstract

Compact silicon-on-insulator (SOI) waveguide thermo-optically tunable Fabry-Perot microcavities with silicon/air Bragg mirrors are demonstrated. Quality factors of Q=4,584 are measured with finesse F=82. Tuning is achieved by flowing current directly through the silicon cavity resulting in efficient thermo-optic tuning over 2 nm for less than 50 mW applied electrical power. The high-Q cavities enable fast switching (1.9 mus rise time) at low drive power (<10 mW). By overdriving the device, rise times of 640 ns are obtained. Various device improvements are discussed.