3C-Silicon Carbide Photonics
Silicon Carbide (SiC) is a wide band gap semiconductor with color centers at visible and near infrared wavelengths that are optically active up to room temperatures. This material also provides high refractive index contrast to air and silica, exhibits significant second order nonlinear properties, high thermal conductivity and strong Young modulus, therefore combining the key properties from several well-studied photonics materials in a single platform.
We have developed photonic crystal and microdisk resonators in 3C-SiC on Si that confine light at telecommunications and visible wavelengths with high quality factor and small mode volume. We also develop arrays of nanopillars in 4H-SiC that could be used site-control of color center emission.
Fig. 1. Left: our positive-tone electron beam lithography process provides a versatile set of photonic crystal structures applicable in waveguiding, cavity-emitter coupling, optomechanics and nonlinear frequency conversion. Right: our negative-tone electron beam lithography process provides arrays of pillars and smallest to date, sub-2 micron, SiC microdisks.
The point-defect size of color centers opens up a new capability to place multiple emitters in a solid state microresonator, previously unachievable with quantum dot-cavity systems. Through modeling of the multi-emitter cavity quantum electrodynamics in SiC, we expect enhanced cavity-emitter coupling rate providing higher operational speeds. As a first step in this direction, we have demonstrated room temperature coupling between whispering gallery modes and intrinsic donor-acceptor luminescence in 3C-SiC. Our goal is to achieve emitter-cavity coupling to an ensemble of color centers with narrow linewidth for applications in ultrafast optical switching.
Fig. 2. Optical coupling between whispering gallery modes and intrinsic luminescence in 3C-SiC microdisks at visible and near infrared wavelengths.
- Visible Photoluminescence from Cubic (3C) Silicon Carbide Microdisks Coupled to High Quality Whispering Gallery Modes, Marina Radulaski, Thomas M. Babinec, Kai Müller, Konstantinos G. Lagoudakis, Jingyuan Linda Zhang, Sonia Buckley, Yousif A. Kelaita, Kassem Alassaad, Gabriel Ferro, and Jelena Vuckovic, ACS Photonics 2, 1, 14-19 (2014).
- Photonic Crystal Cavities in Cubic Polytype Silicon Carbide Films, Marina Radulaski, Thomas M. Babinec, Sonia Buckley, Armand Rundquist, J Provine, Kassem Alassaad, Gabriel Ferro, and Jelena Vuckovic, Optics Express 21, 26, 32623-32629 (2013).