Abstract: Underplating between a metallic plating base and a photoresist deposited reon can be reduced or eliminated by a method of fabricating a microstructure which includes the steps of:(a) depositing a plating base on the adhesion layer;(b) depositing on the plating base a sacrificial layer of a material that reduces or eliminates underplating on the plating base compared to underplating in absence of the sacrificial layer;(c) depositing a photoresist on the sacrificial layer;(d) exposing, developing and removing the exposed photoresist from the substrate to uncover a portion of the sacrificial layer;(e) removing the sacrificial layer portion from the substrate to uncover a portion of the plating base; and(f) depositing a metallic material on the uncovered plating base under the influence of electrical current.

Abstract: Defect-free fluoride glass materials are made by hot isostatic pressing (HIP) of a fluoride glass. The process may be used to manufacture preforms or bulk fluoride glass. The external pressure applied during HIP squeezes bubbles from the glass and permits the use of a wider range of working temperatures than ordinarily available, thereby reducing crystallization defects.

Abstract: An optical transversal filter comprises a plurality of optically power spting devices, e.g., 3.times.3 single mode optical couplers, interspersed with fiber optical delay segments. In a n-column system the number of optical couplers in each column is given by the progression, 1,3,9 . . . 3.sup.(n-1) and only two different lengths of the fiberoptic delay segments are required. Fiber optic delay segments of the appropriate delays are connected to the three outputs of each of the composite such that the fiber optic delay segments connected to the last column provide 3.sup.n taps. The outputs can be combined in a single fiber and multiple inputs can be used. Variable weight output taps are provided by connecting each output to an optical intensity modulator or switch.