Surface plasmon resonance based silicon carbide optical waveguide sensor

In this paper, we investigated a new surface plasmon resonance (SPR) based optical waveguide sensor formed on a wide bandgap semiconductor material – silicon carbide (SiC). The wide bandgap energy of SiC (Eg=2.2 eV of 3C-SiC polytype) enables the waveguide to operate in the visible and near-infrared wavelength range. Assessment of the potential sensing properties was performed by investigating the confinement factor in fundamental transverse magnetic mode (TM 0 ) using the effective index method (EIM). The results show that at the incident light of 633 nm, a confinement factor of 0.95 can be achieved at the refractive index of n =1.45. Comparing to reported non-SPR structure, the confinement factor of SiC SPR sensor was clearly improved over the refractive index range of n =1.3–1.5, and by more than 3.3 times at n =1.35. The improved sensing property by SPR structure combined with the superior chemical/biological inertness of SiC material and compatibility between SiC and Si device manufacturing makes the proposed SiC SPR sensor very promising for chemical sensing and bio-sensing. • Demonstrate a new SPR waveguide sensor on a wide bandgap semiconductor – SiC. • The sensor is capable of operating in visible and near-infrared wavelength ranges. • The confinement factor of the sensor was improved clearly by the SPR effect. • The sensor performance is promising for chemical and biomedical sensing.