Abstract: An interferometer structure is disclosed in which alignment problems are reduced by providing a special retaining structure for the transparent beamsplitter plates. In order to minimize distortion of the beamsplitter plates, the metal housing surfaces, against which they are held, are each coated with a material which has a very slippery and extremely flat surface engaging the surface of the respective beamsplitter plate. The preferred coating material is polytetrafluoroethylene. A glass tool (optically flat) is used during heating (and hardening) of the coating material, for the purpose of insuring an unusually flat coating surface.

Abstract: A spectrometer construction is shown in which the chassis of the spectrometer is fabricated by stamping, punching, and bending sheet metal. The mirror supports and other elements are also formed from sheet metal. Precision locations are assured by tab and slot, or half-shear and recess, matching of the sheet metal parts. The mirrors in the spectrometer (other than those in the interferometer) are secured directly to vertical sheet-metal walls without intervening adjustments. The mirrors have unitary reflection and backing structures formed either by a diamond-cutting lathe, or by precision plastic molding. The same mirror locating means are used both during formation of each curved mirror surface and also in assembling of the mirror body in the spectrometer.

Abstract: A small ruggedized interferometer is disclosed, which can operate efficiently in spite of being subject to ambient mechanical vibrations. A prior art structure was analyzed to diagnose its performance deficiencies. The successful method is a step by step structural solution, beginning with the lowest frequency mechanical vibration resonance in the interferometer, restructuring to raise that frequency, then proceeding to the next lowest mechanical vibration resonance frequency in the interferometer, and so on. The movable mirror is carried by a parallelogram linkage. The minimum resonance in the present interferometer has been raised to approximately 1000 Hertz. A first (lowest) frequency resonance problem solved was due to the motor and its interface with the movable mirror. A second resonance problem solved was due to the vibration of the movable mirror itself.

Abstract: There is disclosed an adjustment structure for use in initially aligning the two arms of an interferometer, by varying slightly the angular position of mirror surfaces. Two "wedge" elements are used behind the mirror, each of which is independently rotatable about an axis perpendicular to the face of the mirror. In order to provide ideal lubrication between the relatively movable flat engaging surfaces, a solid layer of a low friction polymer is used, preferably polytetrafluoroethylene.

Abstract: An apparatus, for photo-luminescent analysis of the surface of crystalline silicon, is disclosed, in which the photons emitted from the sample are passed through a two-beam (or two-arm) interferometer, having the usual beamsplitter, fixed mirror, and movable mirror. The interferometer output is directed to a detector which is a germanium photo-diode, cooled in a Dewar, which also cools the initial electronic circuitry to which the detector output is input. Using the disclosed apparatus, methods are available for readily eliminating the negative effect of the electron-hole-droplet phenomenon, and for utilizing the no-photon region of the spectrum to identify otherwise unidentified impurity (or dopant) materials.

Abstract: An interference spectrometer which analyzes an unknown light beam for determining the presence and amount of particular frequency by passing the light beam through an interferometer with a moving mirror, which transforms the beam into a first signal which represents the inverse Fourier transform of the electrical light beam. An associated laser beam is also processed by the interferometer and detected to give a second signal. The first signal is sampled at each periodic variation of the second to generate a discrete signal which is then digitized. A digital Fourier series frequency component synthesizer synthesizes preselected discrete frequency components of the incoming beam which correspond, for example, to the gaseous components of interest. A particular gas handling apparatus is disclosed which is adapted to handle unstable inhomogeneous gases such as automobile exhaust fumes.

Abstract: An interferometer for analyzing electromagnetic frequency spectra including a movable mirror supported on two air bearings such that the center of support of the bearings continuously coincides with the center of gravity of the movable mirror during the motion of the mirror. The air bearings engage two parallel, spaced apart lateral rods that maintain the optical alignment of the mirror. To facilitate making spectral measurements, the interferometer also incorporates a laser for producing monochromatic light that is directed through a primary beam splitter to provide a periodic fringe pattern as the mirror moves and a white light directed through a secondary beam splitter to provide a reproducible reference point.

Abstract: An interferometer for analyzing electromagnetic frequency spectra including a movable mirror supported on two air bearings such that the center of support of the bearings continuously coincides with the center of gravity of the movable mirror during the motion of the mirror. The air bearings engage two parallel, spaced apart lateral rods that maintain the optical alignment of the mirror. To facilitate making spectral measurements, the interferometer also incorporates a laser for producing monochromatic light that is directed through a primary beam splitter to provide a periodic fringe pattern as the mirror moves and a white light directed through a secondary beam splitter to provide a reproducible reference point.

Abstract: An apparatus, for photo-luminescent analysis of the surface of crystalline silicon, is disclosed, in which the photons emitted from the sample are passed through a two-beam (or two-arm) interferometer, having the usual beamsplitter, fixed mirror, and movable mirror. The interferometer output is directed to a detector which is a germanium photo-diode, cooled in a Dewar, which also cools the initial electronic circuitry to which the detector output is input. Using the disclosed apparatus, methods are available for readily eliminating the negative effect of the electron-hole-dropler phenomenon, and for utilizing the .[.no-photon.]. .Iadd.no-phonon .Iaddend.region of the spectrum to identify otherwise unidentified impurity (or dopant) materials.The questions raised in reexamination request No. 90/001,324, filed Sep. 9, 1987, have been considered and the results thereof are reflected in this reissue patent which constitutes the reexamination certificate required by 35 U.S.C. 307 as provided in 37 CFR 1.570(e).