Abstract: A spectrograph is disclosed generally comprising a radiation source and a dispersion device that includes a plurality of segments arranged adjacently along a plane upon which the radiation is incident, where each of the segments disperses the radiation differently than adjacent segments. In certain embodiments, each segment can be rotated and titled separately from the other segments. In some embodiments, the dispersed radiation is received by a detector in a plurality of spectral channels corresponding to the segments and including radiation of different spectral orders.

Abstract: An optical input system for correcting astigmatism introduced by off-axis reflectors in a spectrograph includes an aspheric mirror producing a correcting factor which compensates for the spectrograph distortions and enables the spectrograph to produce multiple astigmatic light images at its two-dimensional charge-coupled-device output.

Abstract: A monochromatic spectrometer for evaluating contamination changes in the surface condition of lenses, reflectors and similar optical samples in the vacuum of a space mission includes a vacuum ultraviolet beam source redirected from a dispersion grating through a test station and reflected from a mirror to a photodetector. A rotatable carrier supports two or more optical samples, both transmissive and reflective and selectively positions one sample at a time at the test station so that the selected sample modifies the VUV beam according to its surface condition. The mirror is movable from a first position in which it reflects the beam transmitted through a sample to second position in which it reflects the beam reflected from a sample. The sample condition measured by the photodetector, the position of the rotatable carrier and mission elapsed time are recorded in a memory for re-transmission or later read out.

Abstract: A shield for admitting laser beams to a target in a reaction chamber while obstructing exit of target ejected debris from the chamber is formed by coating the opposable faces of two supports with a layer of release agent and a coating protecting the release layer. A bead of transparent epoxy compound is then pressed between the two supports to form an epoxy shield. While the shield is on one support a framing holder is epoxied to the shield.

Abstract: A reflector which particularly reflects light at a selected peak wavelength in the vacuum ultraviolet (VUV) region and which absorbs light outside the VUV, particularly in the visible light region consists of a reflective surfaced substrate such as polished aluminum, a dielectric layer over the reflective surface, and a thin film of one or more of the six, non-radioactive metals tungsten, rhenium, osmium, iridium, platinum and gold. The thickness of the dielectric spacer layer is approximately one fifth that of the selected peak wavelength, and a second dielectric layer of the same thickness may be applied over the metallic thin film.

Abstract: A monochromator has three ports or slits including two entrance slits and an exit slit. A single mirror and a diffraction grating define a first, folded path between an entrance slit on one side of the housing and an exit slit on the opposite side of the housing. The mirror is movable in and out of a second path between the second entrance slit and the grating so that a second path may be completed from the second entrance slit to the grating and thence to the exit slit. Alternatively two of the ports may be used as exit slits and one as an entrance slit.