III-Sb barrier detectors suitable for the mid-wave infrared were grown on GaSb by molecular beam epitaxy. Using both bulk-InAsSb and an InAsSb-InAs strained layer superlattice, operation close to room temperature was demonstrated with cut-off wavelengths of 4.82 μm and 5.79 μm, respectively, with zero-bias operation possible for the bulk-InAsSb detector. X-ray diffraction, temperature dependent dark current and spectral quantum efficiency were measured, and an analysis based on calculated specific detectivity carried out. 1/f noise effects are considered. Results indicate these optimized devices may be suitable as alternatives to InSb, or even HgCdTe, for many applications, especially where available power is limited.III-Sb alloys and quantum structures are being developed as alternatives to HgCdTe or InSb for mid-wave infrared (MWIR) detectors.[1-4] InSb generally requires cooling to 77 K for acceptable levels of performance and, whilst HgCdTe-based sensors generally still offer the highest signal to noise ratios, they suffer from a lack of large-area native substrates, an acute bandgap-compositional dependence at longer wavelengths, [5] uniformity issues and excessive cost. III-Sb alloys benefit from native 4" GaSb and 3" InAs substrates, lower cost, and the possibility for a wide range of heterostructures with lattice matched materials and alloys, e.g. AlAsSb, InAs, InAsSb or InGaAsSb.[6] Cut-off wavelengths between 1.7 μm and (at least) 12 μm can be achieved using various alloys and strained layer superlattices (SLS).[7-9] However, high dark currents due to trap-related processes and surface recombination are frequently problematic; the community has focussed extensively on developing III-Sb barrier detector designs, which address surface and defect related dark currents using AlSb-based electron-blocking barriers.[10-12] These barrier or "nBn" detectors were first reported using InAs and AlAsSb in 2006.[13] Since then, the design has been widely copied and extended to include InAsSb, e.g. [10] InGaAsSb [6] InAs-GaSb SLS e.g. [14,15] and InAsSb-InAs or "Ga free" SLS e.g. [7][8][9]. In

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We demonstrate a novel solid-state spectrometer employing a linear array of resonant cavity enhanced photodiodes (RCE-PDs) with a spatial chirp. By epitaxially grading the thicknesses of the distributed Bragg reflector mirrors, the chirp can cover a total bandwidth of ≥0.1 × λ res where λ res is the resonant wavelength. This new class of sensor is intended for analyzing IR absorption fingerprints and our group has already demonstrated conventional RCE-PDs between 2.2 -7.8 µm. In theory the range between 1.55 and ~12 µm could be served using the same materials. This region covers important spectral fingerprints including chemical and pollutant gases, as well as threat agents including thiodiglycol and VX.