Patent attributes
A polarization switching lidar device is arranged for remote detection and characterization of airborne aggregations of particulates. It includes a pulsed laser, a mirror, a polarizing beam splitter, an actively controlled retarder arranged to be controllably alternated between a zero retardation state and a quarter-wave retardation state such that the transmitted portion of the exiting laser light beam is linearly polarized in a predetermined direction when the actively controlled retarder is in the zero retardation state, while being circularly polarized in a predetermined rotational sense when the actively controlled retarder is in the quarter-wave retardation state. A directable telescoping assembly is arranged to collect photons backscattered by the airborne aggregations of particulates and to redirect the collected portion of depolarized backscattered photons onto the polarizing beam splitter. A photodetector is arranged to generate at least one electronic signal proportional to the collected portion of depolarized backscattered photons.
