Particle detector using laser resonator, e.g. for detecting sub-microscopic particles in air

摘要

The device has a laser resonator (13) and an optical pump source (19). The pump source excites a laser medium (11) to generate laser light in the laser resonator (13). A test region (29) is coated with particles. The test region is inside the laser resonator (13) in the path of the laser light. Thus light in the test region (29) is influenced in a predetermined manner by at least a proportion of the particles in the test region such that the affected light serves as proof of the proportion of particles. The laser medium is preferably a solid state laser medium (11). This may be e.g. a Nd:YAG or Nd:YVO4 or Cr:LiSAF crystal. The optical pump (19) may ne a semiconductor laser.