Compact 405-nm random-modulation continuous wave lidar for standoff biological warfare detection

摘要

A compact bioaerosol standoff system was developed and tested for bio warfare agent stimulant aerosol detection. It used a continuous-wave semiconductor laser diode with an output power of 100 mW and a wavelength of 405 nm. It was modulated with a pseudorandom code at 100 MHz to provide the 1.5 m range resolution for both scattering and fluorescence detection. A 200-mm-diameter Cassegrain telescope and four photon-counting detection channels centered at 405 nm (two polarization detection channels), 450 nm, and 530 nm constituted the optical receiver. A field-programmable gate array chip was controlled to generate the laser driver signal and record four synchronized channel signals. Field tests were performed with stimulant aerosols of Bacillus subtilis, Staphylococcus aureus, and yeast. The detected biological warfare stimulant aerosol lidar was released at ranges of several hundred meters. The preliminary result showed that the fluorescence channel detected the stimulants at ranges up to 90 m and the elastic scattering channel up to 200 m. (C) 2015 Society of Photo-Optical Instrumentation Engineers (SPIE)