Abstract: An optical absorption spectroscopy apparatus includes a field mirror and at least one object mirror configured to reflect transmitted light multiple times between the field minor and the at least one object mirror through a sample volume. At least one fold mirror is configured to allow the transmitted light to double pass across the field mirror. The apparatus can further include a light source and a detector configured to detect an optical absorption spectrum of the light transmitted from the light source through a sample volume.

Abstract: An apparatus is provided that includes a field reflector and a plurality of pairs of object reflectors. The apparatus also includes a plurality of source and detector port pairs, where each source port is configured to pass a beam of radiation, and each detector port is configured to receive a beam of radiation. The source and detector ports of each pair are positioned proximate an outer edge of the field reflector such that an optical axis of the field reflector lies between the respective source port and detector port. The object reflectors and source and detector port pairs are arranged such that each source and detector port pair is associated with a respective pair of object reflectors forming a distinct channel, where the source and detector port pair, and centers of the associated pair of object reflectors, of each channel lie in a distinct plane.

Abstract: An apparatus is provided that includes a field reflector and a plurality of pairs of object reflectors. The apparatus also includes a plurality of source and detector port pairs, where each source port is configured to pass a beam of radiation, and each detector port is configured to receive a beam of radiation. The source and detector ports of each pair are positioned proximate an outer edge of the field reflector such that an optical axis of the field reflector lies between the respective source port and detector port. The object reflectors and source and detector port pairs are arranged such that each source and detector port pair is associated with a respective pair of object reflectors forming a distinct channel, where the source and detector port pair, and centers of the associated pair of object reflectors, of each channel lie in a distinct plane.

Abstract: A light valve such as an active matrix LCD between crossed polarizers, utilizing, for instance, individual transistors to control each "pixel area" of the LCD and storage elements to store video signal data for each pixel, with optically shielded "dead spaces" between pixels to eliminate electric field cross-talk and non-information-bearing light bleed-through, is illuminated with a bright independent light source which creates a video image projected via specialized projection optics onto an internal or external screen without distortions, regardless of the angle of projection onto the screen. Use of heat sinks, IR reflective coatings, heat absorbing optics, optional fluid and a thermistor controlled pixel transistor bias voltage injection servo circuit stabilizes image performance, maintaining accurate color and contrast levels as the LCD changes temperature.

Abstract: A telescope for eliminating on axis coma due to tilt of the secondary mirror in infrared astronomy. The secondary mirror of a reflecting telescope is formed to cause field coma to always be equal and opposite at the optical axis of the telescope to tilt coma regardless of the angle through the secondary mirror is tilted with respect to the optical axis.