Abstract: A method for creating attached features while controlling the depth profile between the features is presented. First the features are formed with a separating barrier between the features. The separating barrier is then etched in a second step with an orientation dependent etchant to attach the two feature. This method can be used to create attached features of relative similar sizes or attached features of disparate sizes.

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.