Patent ID: 8884271

Claim:
A photodetector for detecting luminous infrared radiation of a given wavelength (λ), comprising a stack of layers with: a layer of a partially absorbent semiconductor material; a spacer layer made of a material that is transparent at said wavelength; and a metal mirror structured in two dimensions, the distance (g) between the top of said mirror and said semiconductor layer being smaller than λ, and said mirror containing an array of holes defining an array of metal protrusions with a pitch P of between 0.5 λ/nSC and 1.5 λ/nSC, where nSC is the real part of the refractive index of the semiconductor material, a protrusion width L of between 9P/10 and 3P/4 and a hole depth h of between λ/100 and λ/15.