Portable snapshot infrared imaging spectrometer.

摘要

A practical, field-capable, 3.0 to 5.0 μm mid-wave infrared Computed-Tomography Imaging Spectrometer (CTIS) has been demonstrated. The CTIS employs a simple optical system in order to measure the object cube without any scanning . The data is not measured directly, but in a manner which requires complicated post-processing to extract an estimate of the object's spectral radiance. The advantage of a snapshot imaging spectrometer is that it can collect information about a dynamic event which a standard scanning spectrometer could either miss or corrupt with temporal artifacts.; Results were presented for reconstructions of laboratory targets with sampling up to 46 x 46 x 21 voxels over a variable field-of-view, or 0.1 μm spectral sampling. Demonstration of the snapshot capability has been performed on both static targets and targets with rapidly varying content.; The contents of this dissertation are directed towards two ends. The primary undertaking is a realization of the theoretical model of the CTIS is a practical, field-capable MWIR instrument. The design, calibration, and operation of the MWIR CTIS are explained in detail in the text and appendices.; Of additional interest is the advancement of the theory to improve the design and functionality of the spectrometer. A new algorithm for design of the holographic disperser component of the CTIS is introduced. The design process dramatically extends the set of possibilities for the disperser.; In order to improve the reconstruction potential of the spectrometer, the analytic expressions which describe the CTIS have been expanded into a principal component basis set. The result is a technique for creating an initial estimate of the object and a technique for improving the reconstruction algorithm.