Advances in Spectral Imaging: A Review of Techniques and Technologies

Spectral imaging systems enable a significant leap forward in identifying and characterizing materials and objects through their unique spectral signatures. This review explores the advances in spectral imaging systems (SIS) designs, analyzing both the techniques and technologies. It provides an overview of the fundamental principles of spectral imaging, including different panchromatic, multispectral, and hyperspectral imaging systems. Progress in the design of multispectral imaging (MSI) systems are comprehensively surveyed with focus on the optical technologies employed. Advances in hyperspectral imaging (HSI) system are discussed, covering various acquisition techniques such as staring, snapshot, whiskbroom, and pushbroom techniques. In the case of staring technique, an in-depth examination is provided on different filtering technologies, including dispersive and diffractive optics, acousto-optic tunable filters (AOTFs), Fabry-Perot interferometers (FPI), liquid crystal tunable filters (LCTFs), and linear variable filters (LVFs). A detailed overview and progress in snapshot techniques is provided, followed by a thorough examination of whiskbroom and pushbroom techniques. Finally, it offers insights into the potential future directions in SIS research.