Abstract: An arrayed waveguide grating may include a transversal filter to compensate for dispersion. The characteristics of each of the waveguides making up the waveguide region of the arrayed waveguide grating can be adjusted to achieve the desired compensation.

Abstract: An arrayed waveguide grating may include a transversal filter to compensate for dispersion. The characteristics of each of the waveguides making up the waveguide region of the arrayed waveguide grating can be adjusted to achieve the desired compensation.

Abstract: A method for forming a helical waveguide uses a deposit screen such as tape to prevent the deposit of unwanted material between the turns of the helix. The waveguide is formed by electroplating of nickel on a mandrel. The mandrel has raised portions similar to a screw on which the waveguide is formed. The deposit screen is placed in the recessed areas between the raised areas on the mandrel to prevent the mandrel from being plated in these areas. This prevents the turns of the helix from touching each other. The resultant helix is easily removed without damage to the waveguide or mandrel.

Abstract: An optical waveguide for infrared light includes a series of metal layers. A thick outer layer of nickel is provided for mechanical stiffness to make the structure self-supporting. Thinner inside layers are also provided of metals such as silver, gold and copper which are good heat conductors. Since nickel has a low thermal conductivity, the waveguide can be damaged due to heat build-up. The layers of good conductors spread the heat efficiently to remove this possibility while the nickel continues to provide the necessary strength. A highly-reflective inert inside layer of gold may also be provided.

Abstract: A holographic 1.times.N single-mode fiber optics coupler for coupling a single-mode monochromatic fiber optics input to N single-mode fiber optics outputs. A hologram of the output fiber bundle or the equivalent is recorded and then a reconstructed image is generated by illuminaing the hologram by means of a single-mode input signal on a single-mode optical fiber. The holographically generated image of the original fiber optics bundle is then coupled to the original fiber bundle or a substantially equivalent output fiber optics bundle providing a high efficiency, compact, and low cost 1.times.N fiber optics coupler with self-alignment features.

Abstract: A method and apparatus are provided for the holographic examination of the internal features of cavities and passageways of a structure. The apparatus employs a laser beam source positioned external of the structure coupled to a multilayer fiber waveguide which conveys the reference beam and object beam, in at least two different layers of the multilayer fiber, which combine in a holographic recordation means to form a hologram of the internal features of the structure, or under certain circumstances a holographic interferogram of the selected features is formed.

Abstract: A method and apparatus are provided for the holographic examination of the internal features of cavities and passageways of a structure. The apparatus employs laser beam sources positioned within the structure to form a laser reference beam and laser object beam which combine in a holographic recordation means to form a hologram of the internal features of the structure, or under certain circumstances a holographic interferogram of the selected features is formed.

Abstract: Apparatus and method for transmission of laser radiation in the infrared portion of the spectrum. A 10.6 .mu.m laser beam is focused tangentially upon an inner surface of an elongated synclastic wave guide having a generally oval cross-section, and an output end of the wave guide is directed upon a target. Preservation of spatial mode coherence in the laser beam is demonstrated both theoretically and experimentally.

Abstract: Apparatus and method for synthesizing laser light characterized by a plurality of discrete wavelengths, without competition among different wavelengths. A preferred embodiment of the invention includes a laser resonator having an optical cavity bounded by a first, reflective end plate; a gas-filled chamber having a pair of Brewster windows, within the optical cavity; and a Brewster angle Pockels cell between one Brewster window and the partially reflective end plate. The laser resonator generates red, blue and green laser light simultaneously and the Pockels cell transmits red, blue and green light successively, at a rate of at least 30 cycles per second, so that the resulting laser beam appears white in color.

Abstract: An object-illuminating and imaging system utilizing, in combination, a laser beam as a light source and an optical fiber as a light transmitter. Light-focusing means are provided and the focused laser beam is, in a preferred embodiment of the invention, directed to impinge upon a single, small-diameter optical fiber. Sensing means such as film or a television-type camera may be used visually to reproduce and/or display the illuminated object. A light-flow-disruptive means such as a vibrator, acting upon a collimated line of illumination, serves to reduce objectionable speckle effects ordinarily present in coherent light beams, thus providing enhanced clarity as viewed and in imaged reproductions.