Abstract: A light spectrum measuring apparatus comprises a sensor case on which a window with a glass is provided; a light emitting member and a light receiving member both provided in the case so that light emitted from the light emitting member passes through the glass, is reflected from solution, returns in the case, and is received by the light receiving member, wherein the glass, the light emitting member and the light receiving member are arranged in such a positional relation that positive reflected light which is emitted from the light emitting member and directly reflected by the glass without proceeding in the solution, is not received by the light receiving member.

Abstract: A light emitting element and a light receiving element are installed on a wiring board mounted in a housing case. Light emitted from the light emitting element is irradiated on an object to be detected through a first lens installed in the housing case. Light reflected by the object to be detected is received by the light receiving element through a second lens installed in the housing case. The housing case is formed of a grounded conductive material, and the wiring board is formed of a material having a coefficient of linear expansion equivalent to that of the housing case.

Abstract: A method to achieve good stepper focus and exposure over an entire wafer for a particular mask level before the start of a product run is described. This method can also be used to produce a characterization of lens field curvature (i.e., a surface of optimum focus across the lens) and to characterize lens astigmatism, defocus sensitivity, relative resolution, and other characteristics, and to check the stepper for optical column tilt. The process prevents the complexities of resist development from affecting determination of focus. The process involves forming an array of latent images in a resist and examining the scattered light from the edges of the latent images. Analysis of the scattered light quickly provides information on correct exposure and focus together with lens characteristics over the printing field.

Abstract: A method is disclosed for the preparation of metal reference samples for spectrographic analysis. The method consists of producing a substantially cylindrical preform or blank by spray deposition, followed by the consolidation of the blank in the form of a bar having an appropriate diameter and finally the cutting of the reference samples therefrom. Compared with the prior art methods, the method offers the advantages of an improved chemical homogeneity and low oxygen content.

Abstract: An optical device for the spectral analysis of a light source which comprises a spectrograph assembly including a dispersive element, and a classical collimator. The spectrograph assembly supplies a complete intermediate spectrum at the object focus of the classical collimator and the classical collimator reforms, at its image focus, an image of the dispersive element. The spectrograph assembly is preferably a Czerny-Turner or other type of spectrograph comprising an entry slit, two juxtaposed concave mirrors of the same focal length and a dispersive element placed strictly in the common focal plane of the two mirrors. Most preferably, the classical collimator is the first mirror of the second, similar spectrograph assembly. The device is most advantageous in that it is readily useable for both simultaneous and sequential spectroscopy.

Abstract: A device for the spectral dispersion of light suitable for use in a spectrographic mode with arrays of solid state photo-detectors. Light from an entrance aperture passes through a dispersing prism with two curved, refracting surfaces both operating near their aplanatic conjugates. After being reflected by a concave mirror located behind the prism, light returns through the prism in the opposite direction, the refractions at each face again being nearly aplanatic. Spectrally dispersed images of the entrance aperture are formed on a plane well separated from the entrance aperture and nearly normal to the incident light rays. Good image quality is maintained over a broad range of operating wavelengths simultaneously, allowing large spectral intervals to be surveyed without moving any of the elements of the system.

Abstract: An optical spectrum analyzer comprises an optical waveguide formed of a material allowing propagation of surface acoustic waves therethrough, and a surface acoustic wave generator for generating a surface acoustic wave, the frequency of which changes continuously and which advances in a direction intersecting an optical path of a guided optical wave as light-to-be-analyzed entered to the optical waveguide and advancing inside of the optical waveguide and diffracts and deflects the guided optical wave, in the optical waveguide. A photodetector is provided for detecting the optical level of the optical wave guided, deflected by the surface acoustic wave and radiated out of the optical waveguide. A frequency detector is provided for detecting the frequency of the surface acoustic wave at the time the photodetector detects the optical level of the optical wave guided, deflected by the surface acoustic wave and radiated out of the optical waveguide.

Abstract: A hand-held prism and support structure, in which a positioning element is engageable with the head of a viewer for orientation and manipulation to position the prism as to enable the viewer to receive refracted light from a scene which is in advance of the viewer. The prism has an upper face and a pair of depending and converging faces, the positioning element being engageable with the nose of the viewer. A filter strip comprising different color filters is provided in advance of the prism and one eye of the viewer, there being a prism without a filter in advance of the other eye.A method of color photography includes viewing a refracted and, optionally, color-filtered image of a scene, and photographing the scene using color sensitive film and, optionally, a color filter.

Abstract: An intense broadband continuum light pulse of uniform spectral intensity and short time duration is generated. This continuum pulse is then downconverted in frequency to a region of interest, preferably in the infrared region, by applying it as a pump pulse to a molecular or atomic vapor so as to induce stimulated Raman scattering. The resulting Raman Stokes pulse surprisingly tends to have the same spectral bandwidth, intensity uniformity and time duration as the pump continuum pulse.The downconverted continuum pulse (the Raman Stokes pulse) is then used to probe a sample. The sample converts the uniform spectral intensity distribution of the probe pulse into a nonuniform spectral intensity distribution which contains the absorption spectrum of the sample. This spectrum pulse has the same spectral bandwidth and time duration as the Raman Stokes pulse and is finally upconverted in frequency to a region where the spectrum pulse can be conveniently recorded.