Abstract: A machine for grinding the cavity in a mold for optical lenses has a spherical grinding tool which is precisely positioned with respect to the center line of a rotary table upon which it is mounted by air slides, which air slides move the tool in orthogonal directions. The carriages of the air slides move relative to center rails. A film of air between the top plate of each air slide and the center rail is supplied at a pressure which supports the weight on the carriage. When precise alignment between the grinding tool and the center line is obtained, a first air supply is cut off and a second air supply is maintained to lock the air slides in the position of alignment.

Abstract: A multi-part mold assembly molds glass lenses. A cylindrical sleeve between the top and bottom molds has three cut-outs forming three alignment pads on both ends of the sleeve. These pads are preferably equally spaced around the circumference of the sleeve to constrain the top and bottom molds against rotation about X and Y axes which are orthogonal to the direction of closing of the mold. The alignment pads set the closed vertical positions of the molds. A torus on the bottom mold contacts a tapered opening in a removable sleeve insert to position a glass preform which is held by the insert. A torus on the top mold and a torus on the bottom mold bear against a cylindrical inner surface of the sleeve to precisely align the molds in the X and Y directions.

Abstract: An automotive headlight has a clear unfluted front cover and a reflector which directs light from a source through the front cover in a desired pattern. The reflective surface is smooth and continuous formed of two edge ellipsoids and a center ellipsoid joined in smooth continuous junctions. The center ellipsoid is modified to include a smooth vertical bump and the ellipsoids are tilted off the axis of the headlight. The headlight is formed by a digital computer aided process which includes tracing the paths of a plurality of light rays emanating from a digitally modeled light source, intersecting a reflector modeled by digital shape functions and projected onto a sphere surrounding the reflector. The light intensity across a part of the sphere is compared with the prescribed automotive headlight specifications. The parameters of the shape functions are changed and the process is performed iteratively to produce a light intensity best matching the specifications.

Abstract: Concentrations of dopants are changed while forming a gradient index optical waveguide so that an optimal index profile is produced even though the relationship between concentration and refractive index is not linear. This is accomplished by varying the concentrations of the dopants as a function of the radial distance from the center of said core substantially as:C.sub.i (r)=C.sub.i .degree.+[(l-.xi..sub.i)(r/a).sup..alpha. +.xi..sub.i (r/a).sup.2.alpha. ]C.sub.i.sup.1where C.sub.i (r) denotes the concentration of the i.sup.th dopant as a function of radial distance r, C.sub.i.sup..degree. denotes the concentration at r=o of the i.sup.th dopant, C.sub.i.sup.1 is the total change in concentration of dopant's between r=o and r=a, .alpha. is the selected index profile, and .xi..sub.i are variable parameters relating the concentration of the i.sup.th dopant to radial distance r.

Abstract: An optical waveguide for a communication system includes a graded index core formed from at least three glass-forming compounds with a profile having at least two .alpha.-type index profile terms.The core has a refractive index which is n.sub.c at the center of the core and which varies as a function of the radial distance r from the center of the core substantially as: ##EQU1## where .alpha..sub.i is defined by: ##EQU2## .DELTA.=(n.sub.c.sup.2 -n.sub.o.sup.2)/2n.sub.c.sup.2, n.sub.o is the refractive index of said compounds at r=a,N.sub.c =n.sub.c -.lambda.dn.sub.c /d.lambda. where .lambda. is the wavelength of the light source, and the quantities .DELTA..sub.i are parameters which can be varied provided the condition ##EQU3## is satisfied.

Abstract: A glass optical fiber has multiple cores and a cladding. The index of refraction of all cores is greater than the index of refraction of the cladding and the index of refraction of a first core is greater then the index of refraction of a second core. The change in the ratio of light loss from the first and second cores is detected to identify perturbations of the optical fiber before it reaches a level sufficient for a secure signal to be tapped.

Abstract: A gradient index optical waveguide has an optimal index profile even though the relationship between concentration and refractive index is not linear. This is accomplished by varying the concentrations of the dopants as a function of the radial distance from the center of said core substantially as:C.sub.i (r)=C.sub.i.sup.0 +[(1-.xi..sub.i)(r/a).sup..alpha. +.xi..sub.i (r/a).sup.2.alpha. ]C.sub.i.sup.1where C.sub.i (r) denotes the concentration of the i.sup.th dopant as a function of radial distance r, C.sub.i.sup.0 denotes the concentration at r=o of the i.sup.th dopant, C.sub.i.sup.1 is the total change in concentration of dopants between r=o and r=a, .alpha. is the selected index profile, and .xi..sub.i are variable parameters relating the concentration of the i.sup.th dopant to radial distance r.