Abstract: Tapered optical waveguides (33') can be easily made by using photolithographic masking and etching to define on a substrate (21) a first polymer structure (22) having a substantially uniform thickness and a tapered width. The first polymer structure is heated sufficiently to form a meniscus along its entire length. The fluidity causes the material to redistribute itself such that, rather than being of uniform thickness, it has a thickness that varies with its width; consequently, the thickness as well as the width of the first polymer structure becomes tapered. The first polymer is cooled and hardened to form a second polymer structure (22') that has a tapered width and a tapered thickness as is desirable for a tapered optical waveguide. The second polymer structure itself can be used as a tapered optical waveguide, or it can be used to control the reactive ion etching of the underlying substrate.

Abstract: A diffractive and a refractive microlens component are combined into a doublet lens to obtain imaging properties that are improvements over those achievable using separate components. In one application, diffractive/refractive microlens arrays are arranged to provide a free-space optical permutation interconnect arrangement.

Abstract: An optical waveguide is made by forming successively of light transmitting material a first clad layer (13), a core layer (15) and a second clad layer (18). The core layer has a higher refractive index than that of the first and second clad layers such that the core layer (15) can transmit light along its length as an optical waveguide. A sacrificial layer (14, 17) is formed surrounding at least a first end potion of the core layer. The sacrificial layer is selectively removed as by selective etching such that the first end portion of the core layer is separated from the first and second clad layers. With the end portion so isolated, a lens (22) can be formed on it such that light may be more effectively coupled to or from the core layer. Preferably, the lens is formed by heating the structure sufficiently to form a meniscus on the free end and then cooling it before the reminder of the core layer flows or melts. The cooling hardens the meniscus such that it constitutes an optical lens.

Abstract: Prior to the production of microlenses (29) by the reactive ion etch technique, a pattern of notches (25) is formed in a second surface of a substrate (11) opposite a first surface on which the microlenses (29) are to be formed. Reactive ion etching of the first surface to produce the microlenses is sufficiently deep to reach the pattern of notches, thereby to separate the substrate. The array of notches may define, for example, an array of first areas (26) on the second surface, each area being surrounded by a notch. Photoresist elements (28) are then each located on an area of the first surface corresponding to a first area of the second surface, so that the separation separates the substrate into a plurality of segments (26) each containing only one of the microlenses (29). The notches can be made such that each of the segments (26) is cylindrical so that each of the microlenses formed from the substrate has a circular outer periphery.

Abstract: During a reactive ion etching process (FIG. 5) for making lens elements (15, FIG. 4) in a silica substrate (12), the gas constituency in the reactive ion etch chamber is changed to adjust the curvature of lens elements formed in the silica substrate and to reduce the aberrations of such lens elements. For example, two gases, CHF.sub.3 and oxygen may be supplied to the reactive ion etch chamber and, during the reactive ion etch process, the proportion of oxygen is significantly reduced, which reduces the aberrations of the lens elements formed by the process.

Abstract: A Langmuir-Blodgett monolayer polyimide film and a bulk amorphous polyimide film are in contacting superposed relation to form a composite film having improved moisture resistance. The composite film may be either a free film or provide an insulating coating on the surface of a microelectronics device.

Abstract: A resilient and deformable touch screen that is adapted to be overlaid on the surface of a CRT screen is formed from a semi-rigid plastic frame attached to a flexible plastic pouch filled with a soft resilient material which adheres to the surface of the pouch.

Abstract: A selective metallization process particularly suited for making printed circuit boards comprises the step of treating a substrate having a negative mask thereon with a reactant, e.g., acetic acid, which modifies the surface of the mask without affecting the substrate so as to remove or prevent an active catalytic layer from remaining on the surface of the mask thereby preventing electroless plating on the mask.

Abstract: A method of forming a colloidal wetting sensitizer is disclosed. The method comprises combining a stannous species and a cupric species in an aqueous medium maintained at a pH of between 0.4 and 1.5.

Abstract: A method of removing contaminants from the surface is disclosed. The method comprises coating the surface with a surface active agent having a first surface energy and into which the contaminants are combined, applying thereover a higher surface energy colloidal sol and then allowing sufficient time for the first surface energy material with the contaminants combined therewith to migrate through the colloidal sol so as to remove the contaminants from the immediate vicinity of the substrate surface. The surface may then be treated by exposing it to an acid or base to remove the migrated surfactant layer thus removing the trace of contaminants.

Abstract: A method of forming a colloidal wetting sensitizer is disclosed. The method comprises combining a stannous species and a cupric species in an aqueous medium maintained at a pH of between 0.4 and 1.5.

Abstract: A method of selectively depositing a metal on a surface is disclosed. The method comprises selectively coating a surface with a surface active agent, having a first surface energy, to form a coated surface having a coated portion capable of burying a higher surface energy material applied thereto and an uncoated surface pattern not so capable. The selectively coated surface is then treated with a solution, having a second surface energy higher than the first, comprising a species selected from the group comprising (1) a species capable of reducing an activating metal ion to an activating metal and (2) an activating metal species capable of participating in an electroless metal deposition, to form a surface having the species deposited atop the uncoated pattern.

Abstract: A continuous length, flexible, polymeric substrate has thin layers of copper clad to opposite sides thereof. Patterns of dry photopolymer material are applied to and mask selected portions of the copper to leave exposed other selected portions of the copper. The copper clad substrate is guided by a series of cathodic electrode rollers exterior of a copper plating bath into successive passes through the bath. Portions of the exposed copper contact the electrode rollers and couple the cathodic potential thereof to the bath to effect the plating of copper from the bath onto the exposed selected portions of the copper.Prior to initial engagement with the cathodic rollers, a series of protrusions are formed in portions of the exposed copper at a height relative to the thickness of the photoresist material sufficient to insure that the copper, by virtue of the protrusions, contacts the electrode rollers to facilitate the plating operation notwithstanding the intervening photoresist material.