Super-Sensitive Optical Biosensor with a Spectrometer on a Chip

Abstract

ABSTRACTWe have proposed a super-sensitive optical biosensor design by integrating a circular-hole defect with an etched diffraction grating (EDG) spectrometer based on amorphous silicon photonic platforms. With an appropriate defect diameter, the sensor chip can contribute to ∼ 12450 nm/RIU sensitivity and an acceptable fabrication tolerance. The influence of the circular-hole defect on the performance of sensing applications is also characterized. The results show that there is a free spectral range for the resonant scattering behavior and a limited linear sensitivity range for optical sensing applications in terms of the defect size. The results also indicate that a slight ellipticity has limited influence on the operational sensitivity.