Optical stand-off detection of biological and chemical hazards — Prospects and concerns

Lidar technology in terms of real-time stand-off detection of both biological and chemical airborne materials is discussed in this paper. If faced to optical electromagnetic radiation, both types of species present different fingerprint features. For this reason lidar architectures for chemical and biological detection also differ significantly. Biological stand-off detection is based on UV-laser induced fluorescence and depolarization phenomena (LIF-DEPOL-LIDAR), while chemical detection can be performed in the regime of LWIR absorption spectra analysis (DIAL - Differential Absorption Lidar). Due to real market demand, both technologies have been discussed by many authors and a lot of practical research have been done in recent years in this field, however no actual implementation in the form of a regular military equipment was reported so far worldwide. The discussion in this paper also deals with the main reasons for such situation. Nevertheless, chem/bio lidar technique does not have any competitors in terms of range of detection and processing time, so its further progress is inevitable.