Abstract: Embodiments in accordance with the present invention relate to an apparatus for optical characterization of aerosol particles, including a laser source; a beam splitter configured to split the laser into two orthogonally polarized optical beams, wherein one component of the orthogonally polarized optical beam is deflected from the second component of the polarized optical beam at a predetermined angle; a cylindrical lens for collecting the two orthogonally polarized optical beams and focusing each of the optical beams to an interrogation region; an inlet positioned to deliver the sample gas including particles to the interrogation region as a single particle gas stream through the interrogation region; an ellipsoidal mirror positioned at a non-perpendicular angle adjacent to paths traversed by the polarized optical beams to reflect scattered optical beams from the particles traversing through the interrogation region; and a photodetector for measuring the scattered optical beams reflected by the mirror.

Abstract: Embodiments in accordance with the present invention relate to an apparatus for optical characterization of aerosol particles, including a laser source; a beam splitter configured to split the laser into two orthogonally polarized optical beams, wherein one component of the orthogonally polarized optical beam is deflected from the second component of the polarized optical beam at a predetermined angle; a cylindrical lens for collecting the two orthogonally polarized optical beams and focusing each of the optical beams to an interrogation region; an inlet positioned to deliver the sample gas including particles to the interrogation region as a single particle gas stream through the interrogation region; an ellipsoidal mirror positioned at a non-perpendicular angle adjacent to paths traversed by the polarized optical beams to reflect scattered optical beams from the particles traversing through the interrogation region; and a photodetector for measuring the scattered optical beams reflected by the mirror.

Abstract: Embodiments of the present invention relates to a system for measuring trace species in a sample gas. The present invention uses an open-path configuration including an optical cell with mirrors at each end, a long slotted rod with holes in the end for an optical bean to pass through, and a slotted tube surrounding the slotted rod such that air can pass through the rod in a transverse direction when the slots are aligned. Embodiments of the present invention further includes a flow configuration for purging sample gas from the optical cell, and cleaning mirrors, with calibrated or zero air through inlets in front of each mirror.