Laser-diode-based optical sensor for laser particle counter

A laser-diode based optical sensor for laser particle counter is described,nd some calculated and test results are reported in this paper. A low-powered 650 nm laser diode is used as the light source. The optical system of the sensor is a right- angle scattering optics, which consists of an illumination system and a wide-angle collection system for scattered light. The sensor features high counting efficiency and high signal- to-noise ratio for smaller particles.