Patent ID: 8054464

Claim:
A polarization switching lidar device for remote detection and characterization of at least one airborne aggregation of particulates comprising: a source of a polarized pulsed laser light beam; a direction controlling mirror arranged to reflect the polarized pulsed laser light beam and redirect the reflected polarized pulsed laser light beam; a polarizing beam splitter arranged to intersect the reflected polarized pulsed laser light beam and to redirect a portion of the reflected polarized pulsed laser light beam; an actively controlled retarder arranged to intersect the redirected portion of the reflected polarized pulsed laser light beam, and to be controllably alternated between a zero retardation state and a quarter-wave retardation state such that the transmitted portion of the polarized pulsed laser light beam exiting the actively controlled retarder is linearly polarized in a predetermined direction when the actively controlled retarder is in the zero retardation state, while the transmitted portion of the polarized pulsed laser light beam exiting the actively controlled retarder is circularly polarized in a predetermined rotational sense when the actively controlled retarder is in the quarter-wave retardation state; a directable telescoping assembly arranged to intersect the transmitted portion of the polarized pulsed laser light beam exiting the actively controlled retarder and to controllably redirect the intersected polarized pulsed laser light beam into a predetermined space angle while collecting at least a portion of depolarized backscattered photons from the scanned polarized pulse laser light beam backscattered by the at least one airborne aggregations of particulates, and to redirect the collected portion of depolarized backscattered photons onto the polarizing beam splitter; an optical matcher arranged to collect a fraction of backscattered photons exiting the polarizing beam splitter and focus the collected fraction of depolarized backscattered photons onto a photodetector arranged to generate at least one electronic signal proportional to the collected portion of depolarized backscattered photons.