The exploitation of optical forces near photonicbiosensors in order to improve detection limits

Rapid detection of individual virus particles and other pathogens via portable, easy-to-use devices could greatly improve public health and safety. On-chip optical resonators are promising candidates for this application. Fluid samples can be delivered to the resonator via on-chip microfluidic channels, and particles detectably perturb the resonant mode when they diffuse from flow near to the resonator. However, reliance on diffusion from flow institutes a tradeoff between overall sensitivity and detection time. More sensitive or more rapid detection requires a more effective transport mechanism. In this work, optical forces are explored as an additional transport mechanism to silicon photonic crystal resonators. Simulations and experiments are performed to measure the enhancement in the minimum particle concentration detectable by previously studied geometries, and the results are used to design a more effective device geometry.