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The availability of a relatively low-cost miniature integrate dIR spectrometer facilitates the application of IR spectroscopy to numerous spectral analysis and identification tasks. Recent advances in semiconductor material processing now provide the technology for the development of planar optical waveguides that exhibit good transmission characteristics in the mid-IR spectral range. Chalcogenide and fluoride glass fibers are commercially available which allows their use for coupling light to the integrated spectrometer. Integration of the slab waveguide structure with an input IR fiber and an output IR detector array thus results in a very compact device that can be used in numerous field and industrial applications such as gas detection, water analysis, chemical process monitoring, geological and agricultural surveys, and pollution monitoring. In the present work, these new materials and technologies have been exploited for the implementation of a miniature integrated optic SPECtrometer (IOSPEC) for the 2 to 6 micrometers spectral range. In the developed miniature spectrometer, broadband light is coupled into the spectrometer through an IR fiber, then subsequently dispersed into its spectral components by a diffraction grating made by anisotropic etching of silicon and finally focused on an IR detector array. This paper discusses some of the performance and design aspects of the current third generation IOSPEC technology; namely the use of IR fiber arrays in order to improve the device throughput and resolution, and the coupling of IOSPEC to advanced linear IR detector array technology.
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