PECVD Silicon Carbide Waveguides for Multichannel Sensors

This work presents the characteristics of an evanescent wave sensing system based on Plasma Enhanced Chemical Vapour Deposition (PECVD) Silicon Carbide (SiC) waveguides. Thin SiC films have been deposited onto Si substrates with a SiO₂ film acting as a cladding layer around the carbide core. In the sensor, the evanescent tale of the light traveling in a waveguide senses an absorbant medium placed above the waveguide. By using a 1times2 power splitter the sensor is calibrated using one arm as a reference. We show that the sensitivity of such a SiC sensor is improved, compared to Silicon Nitride (SiN) sensor. Further SiC waveguides are used in 1XN optical power splitters making the platform suitable for multiple readout and multichannel sensors.