Monolithically integrated, resonant-cavity-enhanced dual-band mid-infrared photodetector on silicon

In this paper, we present experimental demonstration of a resonant-cavity-enhanced mid-infrared photodetector monolithically fabricated on a silicon substrate. Dual-band detection at 1.6 μ m and 3.7 μ m is achieved within a single detector pixel without cryogenic cooling, by using thermally evaporated nanocrystalline PbTe as the photoconductive absorbers. Excellent agreement between theory and experiment is confirmed. The pixel design can potentially be further extended to realizing multispectral detection.