Thermo-optic characterization of silicon carbide microdisks for infrared applications

Silicon carbide (SiC) is a well-known material in the field of high temperature and high voltage electronics thanks to a high thermal conductivity, high electric field breakdown strength and high maximum current density [1]. Simultaneously with a strong inertness and a low thermal expansion, this makes silicon carbide a good material for extreme condition sensing [2]. The fact that the cubic structure (3C) of SiC can be grown on silicon makes it compatible with most of the silicon technology. At the same time, silicon carbide exhibits some good optical properties particularly promising for non-linear photonics from the near to the mid infrared range [3-4]. Its high refractive index (n∼2.6 at λ = 1.5μm) allows a good light confinement. Studies on other crystallographic structures [5] suggest that 3C-SiC may exhibit good non-linear properties with a nonlinear index comparable to silicon and nonlinear loss — often detrimental to non-linear processes — virtually inexistent thanks to wide its bandgap [6]. In this work, we report the linear optical and thermal characterization of silicon carbide microdisks on a silicon substrate designed for non-linear operations from near to mid-infrared wavelength.