Infrared imaging spectroscopic system based on a PGP spectrograph and a monochrome infrared camera

Abstract

Hyperspectral imaging spectroscopy has been widely used in remote sensing. However, its potential for applications in industrial and biological fields is enormous. Observation line spectrographs, based on the reflectance of the material under study in each field, can be obtained by means of an imaging spectrometer. In this way, imaging spectroscopy allows the simultaneous determination of the optical spectrum components and the spatial location of an object in a surface. A simple, small and low-cost spectrometer, such as those ones based on passive Prism-Grating-Prism (PGP) devices, is required for the abovementioned application fields. In this paper a non-intrusive and non-contact near infrared acquisition system based on a PGP spectrometer is presented. An extension to the whole near infrared range of the spectrum of a previously designed system in the Vis-NIR range has been performed. The reason under this investigation is to improve material characterization. To our knowledge, no imaging spectroscopic system based on a PGP device working in this range has been previously reported. The components of the system, its assembling, alignment and calibration procedures will be described in detail. This system can be generalized for a wide variety of applications employing a specific and adequate data processing.