Abstract: A process for the production of polished block single mode, evanescent wave directional optical couplers. The process comprises producing a plurality of discrete coupler halves, each coupler half having an optical fiber imbedded in a substrate. The coupler halves are then ground to remove a small portion of the cladding of the optical fiber to produce an oval shaped area of defined dimensions of the exposed fiber. The ground coupler halves are mounted in a first holder in a coplaner manner and further worked to a end point determined by an evanescent coupling measurement. A pair of coupler halves are secured together such that the optical fibers are in optical contact and in effective fusion with each other.

Abstract: A single mode, evanescent wave, fiber optic coupler. The coupler comprises a pair of substrates, each substrate having an optically worked fiber embedded therein and wherein the substrates are secured together such that the optical fibers are in optical contact and are in effective fusion with each other.

Abstract: A novel apparatus for the measurement of color of a sample which comprises an illumination means to illuminate the sample, an electro-optical sensing head to receive the light from the illuminated sample and to output electronic signals and an electronic processing unit adapted to process the signals. The system uses, in the preferred embodiment, a moving spatial filter to modulate a spectrum and a masking means to selectively mask the light from the modulated spectrum. A reference optical path and reference light signals are produced for subsequent processing with the light from the sample, corrected for any errors produced and processed in an analogue electronic unit to produce the tristimulus values X, Y, Z and the chromaticity coordinates x, y of the sample with respect to CIE standards for luminance and chromaticity values.

Abstract: A novel device for use as an additive lamphouse in contact printing. White light is emitted by a source, collimated and then passed through a dispersion element to form a spectrum. The light is then selectively attenuated by wavelength to allow exact control of the color mixture of the light which falls on the negative and the positive contact. The use of a dispersion element rather than the dichroic principle of the prior art allows selective control of the color mixture of the light incident to the negative and thus to the contact by providing an improved control of the homogenuity of the color across the illuminated field. Also the problem of "color wedging" has been markedly reduced. The contact printer according to the present invention is more compact than those of the prior art and may be produced at a reduced cost.

Abstract: A teaching aid for demonstrating the component pure spectral colors of white light and the effect of selective recombination thereof. It utilizes the diffraction principle to produce a spectrum from white light and selectively filters the spectrum. By splitting the filtered light prior to recombination, it is possible to project an image of the selective filter and the recombined selectively filtered light adjacent to each other on a projection screen. Thus, the effects of the variation of the filter is shown directly by a variation in the color and intensity of the recombined light.