Novel standoff detection system for the classification of chemical and biological hazardous substances combining temporal and spectral laser-induced fluorescence techniques

Abstract

In the last decades the potential risk of human exposure to chemical and biological hazardous material is increasing, due to the technological progress and the demographic growth. Therefore, the demand for a detection system which identifies possible threats from a distance is increasing. In this scope, we present a novel experiment investigating the classification prospects of chemical and biological samples at stand-off distances. The system utilizes the spectral and temporal behavior of laser induced fluorescence excited with laser pulses of two different UV excitation wavelength. Furthermore fast data acquisition using a relatively small spectral resolution of 32 Channels per excitation wavelength is investigated. The fluorescence lifetime of most chemical and biological samples lies between 0.1ns to several 10ns and may help to classify the investigated sample. In our approach we use a small part of the fluorescence signal of for distinct spectral channels of the detection system to investigate the possibilities of discrimination on the basis of temporal fluorescence information. First measurements of the fluorescence’s temporal behavior of suspensions as well as a comparison of the new setup with our setup utilizing an iCCD camera with 1096 channels for data acquisition are presented.