Systems and methods for use in detecting harmful aerosol particles

In an environment having fluid containing a plurality of particles, wherein the fluid flows in a direction such that particles within the fluid pass through a region of space, a particle detection method, comprising:

• using an emitter to emit excitation energy into the region while the fluid is flowing though the region so that a particle in the fluid is illuminated by the excitation energy, whereby, in response to the exposure of the particle to the excitation energy, elastic and/or inelastic emissions are produced;
• separating the elastic and/or inelastic emissions into two or more emission spectral regions;
• separately directing the spectral region-separated emissions into optical fibers or energy waveguides, with the fibers or waveguides of sufficiently different lengths such that the spectral region-separated output of each fiber or waveguide arrives at a single detector at distinct times such that each spectral region-separated emission can be separately measured at the output of the detector;
• using a second emitter to emit second excitation energy into a second region while the fluid is flowing through the second region so that a particle in the fluid is illuminated by the second excitation energy, whereby, in response to the exposure of the particle to the second excitation energy, second elastic and/or inelastic emissions are produced;
• using a second detector positioned to receive the second elastic or inelastic emissions from the particle;
• and
• in response to the second detector receiving at least a predetermined amount of emissions from the particle, generating a signal, wherein the signal is configured to cause the first emitter to output an excitation pulse such that the particle is illuminated by the excitation pulse.