RESEARCH

Nanophotonic Devices

Nano-patterned dielectric structures, such as photonic crystals, can provide outstanding control of light propagation and resonant effects. We have developed an electron beam lithographic process that generates features as small as 200 nm in 3C-SiC heteroepitaxially grown on a silicon wafer and in bulk 4H-SiC. This nanofabrication process can be used to generate devices needed for waveguiding, cavity quantum electrodynamics, optomechanics, and nonlinear photonics.

Spin-Photon Interfaces

Color centers provide a photon-interface to electron spins which can be used as quantum bits and nanoscale magnetic sensors. To more efficiently manipulate and read out the electron-spin state with a laser pulse, we have developed nanopillar array in an irradiated 4H-SiC wafer. The advantages of this approach are scalability, small footprint, efficient optical interface, room temperature operation, excellent optical and spin properties.

Purcell Enhancement of Color Centers

Color centers are excellent solid-state quantum emitters that can be used as quantum cryptographic single photon sources and luminescing bio-labels. Their emission rate can be increased through coupling to a microcavity owing to the Purcell effect. We have developed a hybrid nanodevice comprising of a color center rich nanodiamond and a 3C-SiC microdisk on a silicon wafer. The shared whispering gallery mode modifies color center emission properties quintupling its optical signal.

Quantum Light Generation

Color centers in silicon carbide and diamond can serve as an ensemble of nearly-identical emitters due to their small inhomogeneous broadening. This characteristic is unprecedented among solid-state quantum emitters and can be used to achieve collective coupling to a common nanocavity. Studying emission and coherence effects in such a system, we have identified novel mechanisms for robust and high-quality generation of quantum light in the form of single- and three-photon emission.

All-Optical Circuits

Nonlinearities in III-V nanocavities can be utilized for the implementation of optical coherent circuits for fast and low-power all-optical computing. We develop a photonic architecture based on gallium arsenide photonic crystal cavities that communicate via silicon nitride bus waveguide and are tuned into a common resonance using chromium microheaters.