Design Of A Spectral Imaging System Based On A PGP Component

Spectral imaging technique is a new acquiring method that fuses optical imaging and spectroscopy. It can simultaneously acquire spatial image and spectral information of objects and has the advantage of union of imagery and spectrum. This kind of multi-dimensional imaging technique is one of the most important research areas now.The principle of spectral imaging systems is introduced in this thesis. And various kinds of spectroscopic techniques are described in brief. A novel imaging spectrometer with a cemented Prism-Grating-Prism (PGP) is investigated and designed. The method to determine the index parameters of the PGP imaging spectrometer and its fore-optics is described. Based on the fact that the spectral lines of prism and grating bend oppositely, the principle of the line bend correction of the PGP spectroscopic element is investigated. A holographic volume phase transmission grating is used in the PGP element. It is shown that it has high diffraction efficiency within its visible working wavelength range. It is apt to cement with the two prisms and then to form a compact direct-vision dispersion device. The same structure is used for its collimating and imaging lens so that they are suitable for mass production. Their aberration correction is analyzed. The PGP imaging spectrometer meeting the requirement of practical usage is optimized. The evaluation of its imaging quality and the analysis and assignment of its tolerance are presented. Its opt-mechanical design and optical alignment is also considered.The designed PGP imaging spectrometer has the significant advantages of direct vision, compactness, and portability. It has the potentiality to be used in microscopic hyperspectral imagers and hyperspectral imaging remote sensors.