Abstract: An interferometer including a beamsplitter and fixed and movable cube corner reflectors is adapted for use in a Fourier-transform infrared (FTIR) spectrometer. The spectrometer includes a cast metal base, such as of aluminum, with the interferometer including an IR source housing formed integrally with the base for dissipating heat via conduction. The IR source housing is hollow and open at the top for receiving a removable opaque printed circuit board (PCB) which is coupled to and provides support for and electrical current to an IR source within the housing. The housing includes two apertures in lateral portions thereof. An IR beam is directed by the source through a first aperture to the Michelson interferometer, while a second aperture is adapted to receive a fiber optic light guide to allow for direct viewing of the IR source in a safe manner without removing the PCB cover of the housing.

Abstract: A dual beam Fourier transform spectrometer produces two beams from a single infrared (IR) source. The beams are directed through a sample region, with one beam transiting a sample and the other beam transiting a reference cell. The sample and reference beams are then directed to a Michelson interferometer with cube corner retroflectors for optically cancelling the background signal from the separate sample and reference beams and for optically combining the sample and reference beams in an optically accurate and stable manner. The single combined beam, which contains the difference interferogram is directed to a single detector.