Microcavity array IR photodetector

An original microcavity array IR photodetector is proposed and the sensitivity and response time of its pixels are calculated. A photosensitive element represents a composite silicon microcavity made of two optically coupled closed waveguides on a dielectric substrate whose resonance wave depends on its temperature. This dependence is used to detect IR radiation which heats an absorbing element and the composite microcavity thermally coupled with this element. It is shown that for a spatial resolution of 45 μm, the time response is 30 ms and the sensitivity is 10^-3 K at the IR radiation power of ~4.7 × 10^-8 W element^-1.