Abstract: A spectrally resolved monochromatic light is provided which generally comprises an incoherent small source lamp, a concave grating for spectrally resolving the wavelengths of the light to obtain a particular wavelength, and an optical fiber for collecting and transmitting the particular wavelength. The light source can also have more than one optical fiber output, each having a different monochromatic wavelength. An order sorting device, such as a filter or dichroic mirror can be used to filter out the shorter wavelength radiation resulting from higher grating orders.

Abstract: An apparatus for providing an astigmatically-reduced image with a spectroscopic instrument is disclosed which comprises a collimator which collimates electromagnetic radiation; a cylindrical mirror which receives and reflects the collimated electromagnetic radiation; a diffractor having a surface with a plurality of diffraction rulings inscribed thereon for diffracting electromagnetic radiation directed from the collimator; and a focuser which collects, focuses and directs diffracted electromagnetic radiation and directs it towards an exit aperture. In the preferred embodiment, the cylindrical mirror comprises a concave cylindrical mirror positioned such that the cylindrical axis is substantially normal to rulings on the diffractor. In another preferred embodiment, the cylindrical mirror is convex and is positioned such that the cylindrical axis is substantially parallel to rulings on the diffractor.

Abstract: An improved multiple grating spectrograph is provided comprising a grating changer for mounting gratings, and rotatable about an axis substantially perpendicular to grating lines such that changing from one grating to another preserves the wavelength-selecting angle of incidence of electromagnetic radiation. The grating changer preferably includes a grating holder, and an actuator for moving the holder about the axis.

Abstract: A power driven micrometer for engaging a workpiece surface has a rotatable screw and a motor for rotatingly driving the screw. The screw and motor are secured together for longitudinal travel as a unit, the screw being threadedly engaged and supported by a nut in the micrometer casing. A key precludes rotation of the motor relative to the casing while enabling longitudinal travel of the motor relative to the casing.