Abstract: A photodetector for detecting the polarization or wavelength of incident infrared radiation (IR) is described. The polarization sensitive photodetector operates using two sets of patches and corresponding cavities, the first set resonating with IR having a first polarization, while the second set resonates with IR having an orthogonal, second polarization. The polarization sensitive photodetector thus outputs two signals, proportional to the first and second polarizations, respectively. The wavelength sensitive photodetector operates using two sets of patches and corresponding cavities, the first set resonating at a first IR wavelength, while the second set resonates at a different IR wavelength. The wavelength sensitive photodetector thus outputs two signals, proportional to the first and second wavelengths, respectively. The patches have a length corresponding to odd multiples of the effective wavelength of the IR, while the thickness of the photodetector is typically one fourth of the effective wavelength.

Abstract: A photodetector for detecting infrared radiation (IR) using a slab waveguide is described. The slab waveguide photodetector operates by resonating transverse magnetic or electric modes within the slab from the incident IR. An IR absorbing layer is located within the slab waveguide photodetector where the magnitude of the electric field vector is greatest. This permits the use of a thinner IR absorbing layer without sacrificing photoresponse. Multi-color slab waveguide photodetectors are permitted because multiple transverse magnetic or electric modes resonate within the slab waveguide. A reflective or transmissive grating is used to launch the IR into the IR absorbing layer through a cladding or antireflection layer.