Principles , Instrumentation , and Applications of Infrared Multispectral Imaging , An Overview

An infrared (IR) multispectral imaging spectrometer is an instrument that can simultaneously record infrared spectroscopic and spatial information of a sample. Chemical and physical properties of the sample can be elucidated from such images. In a multispectral imaging instrument, a camera is used to record the spatial distribution of the sample, and the spectral information is obtained with a dispersive device. This overview article describes operational principles and recent development of various components used in IR multispectral imaging instruments, including the electronic dispersive devices (acousto-optic tunable filter and liquid crystal tunable filter) and nearand middle-IR cameras (InGaAs, InSb, HgCdTe, and QWIP cameras). Recent applications and unique use of the IR imaging instruments will be described followed by discussion of the future prospects of the technique.