Abstract: The present invention provides an optical analyzer having illumination optics that include a light source, such as a laser or other source, adapted to emit a collimated, or approximately collimated, light beam, and a focusing lens that focuses the beam onto a focus spot within a detection region, wherein the focusing lens is mounted in a lens positioning apparatus that allows for precise positioning of the focus spot within the detection region. The lens positioning apparatus comprises a lens holder adapted to rotate through a small angle around a pivot axis parallel to the optical path, such that the lens holder rotates in a plane perpendicular to the optical path, and an actuator adapted to provide an angular displacement of the lens holder around the pivot axis. The lens holder holds the focusing lens at a first distance from the pivot axis, and is coupled to the actuator at a second distance from the pivot axis, wherein the second distance is larger than the first distance.

Abstract: The invention provides an apparatus including (a) a frame having a boundary plane; (b) a flow chamber supported by the frame, the flow chamber placed a distance from the boundary plane; (c) a radiation source, the radiation source directed away from the flow chamber and away from the exterior side of the boundary plane, and (d) a first reflective surface placed to direct a radiation beam in a path crossing the boundary plane to the flow chamber; (e) one or more reflective surfaces placed to direct a radiation beam from the radiation source to the first reflective surface, the path from the radiation source to the flow chamber being at least 1.5 times the distance from the flow chamber to the boundary plane.

Abstract: The invention provides an apparatus including (a) a frame having a boundary plane; (b) a flow chamber supported by the frame, the flow chamber placed a distance from the boundary plane; (c) a radiation source, the radiation source directed away from the flow chamber and away from the exterior side of the boundary plane, and (d) a first reflective surface placed to direct a radiation beam in a path crossing the boundary plane to the flow chamber; (e) one or more reflective surfaces placed to direct a radiation beam from the radiation source to the first reflective surface, the path from the radiation source to the flow chamber being at least 1.5 times the distance from the flow chamber to the boundary plane.

Abstract: The invention provides an apparatus including (a) a frame having a boundary plane; (b) a flow chamber supported by the frame, the flow chamber placed a distance from the boundary plane; (c) a radiation source, the radiation source directed away from the flow chamber and away from the exterior side of the boundary plane, and (d) a first reflective surface placed to direct a radiation beam in a path crossing the boundary plane to the flow chamber; (e) one or more reflective surfaces placed to direct a radiation beam from the radiation source to the first reflective surface, the path from the radiation source to the flow chamber being at least 1.5 times the distance from the flow chamber to the boundary plane.