Patent ID: 8213010

Claim:
A method of bio-threat detection, using fluorescence interrogation applications, to classify particles traversing top and bottom laser beams in a depolarization velocimetric module having a diode laser source and computer automated instrumentation, the method comprising: concentrating aerosol particles in a front end aerosol particle concentrator subsystem; interrogating concentrated aerosol particles, using fluorescence interrogator applications, to classify aerosol particles traversing a top laser beam and a bottom laser beam in the depolarization velocimetric module, wherein interrogating aerosol particles includes: transmitting a single beam from the diode laser source, splitting, using a birefringent crystal, the single beam into a plurality of beams each of which having orthogonal polarizations, directing collected light of the plurality of beams into a first detector channel and a second detector channel, sampling total elastic scatter in the first detector channel, sampling polarized elastic scatter in the second detector channel, identifying, using differences in polarizations of scattered light, when aerosol particles are traversing one of the top laser beam and the bottom laser beam, determining a ratio of polarized elastic scatter to total elastic scatter, performing data analysis, instrument timing and system control operations in a data analysis, instrument timing and system control subsystem, using the computer processor for outputting trigger signals to a bio-threat particle collector subsystem, and collecting bio-threat aerosol particles in the bio-threat particle collector subsystem.