Abstract: The planar waveguide converter is a silica-glass, bi-directional planar waveguide converter, providing conversion from an input from a single-mode waveguide to an output for a three or four-mode waveguide. Conversion takes place through an intermediate stage of a pair of two-mode waveguides. In the initial stage, the input from the single-mode waveguide passes through a V-shaped, graded-index mode slicer, where it is converted into a pair of two-mode signals. In the intermediate stage, each of the two-mode signals is received by a corresponding diamond or quadrilateral-shaped phase shifter. The output of each phase shifter is transmitted to an M-shaped, graded-index mode combiner, which outputs either a three or four-mode signal.

Abstract: The three-dimensional space-division Y-splitter for multicore optical fibers (MCF) is a 3-D device that depends on space-division splitting (SDS) by double-hump graded-index (DHGI) in a rectangular waveguide. It includes multiple single Y-splitters, each one being dedicated to one MCF core. Each Y-splitter layer has three stages, including an expander; a DHGI-SDS; and a separator. The net result of the Y-splitter is that the signal in a single multi-core fiber input has its optical power split 50-50 between two multi-core fiber outputs without an intermediate single-core single-mode fiber (SMF) conversion stage.

Abstract: The variable optical splitter system includes a V-shaped optical splitter for use in planar lightwave circuits (PLCs), photonic integrated circuits (PICs), etc. The V-shaped optical splitter has first and second optically transmissive branches sharing a common optically transmissive base, where the first and second optically transmissive branches each define an optical waveguide. The first and second optically transmissive branches are symmetrically angled about a central longitudinal axis. A light source directs a light beam to a laterally extending input surface of the optically transmissive base. The light beam travels parallel to the central longitudinal axis. The optical power splitting ratio is directly proportional to the input beam's displacement from the central longitudinal axis, permitting selective tuning of the ratio during design of the splitter.

Abstract: The three-dimensional space-division Y-splitter for multicore optical fibers (MCF) is a 3-D device that depends on space-division splitting (SDS) by double-hump graded-index (DHGI) in a rectangular waveguide. It includes multiple single Y-splitters, each one being dedicated to one MCF core. Each Y-splitter layer has three stages, including an expander; a DHGI-SDS; and a separator. The net result of the Y-splitter is that the signal in a single multi-core fiber input has its optical power split 50-50 between two multi-core fiber outputs without an intermediate single-core single-mode fiber (SMF) conversion stage.

Abstract: The optical absorber for long-wave infrared radiation includes a nano-plasmonic gold structure arrayed on an absorbing dielectric substrate in an alternating checkerboard-type pattern. A plurality of plasmonic cells are formed on an upper surface of the absorbing dielectric substrate, which can be, for example, a silicon nitride (Si3N4) substrate. The plurality of plasmonic cells are arrayed in a regular rectangular grid pattern, with each plasmonic cell having a plurality of elongated strips, each extending along an identical axis of orientation within the plasmonic cell. Adjacent ones of the plasmonic cells are oriented orthogonally with respect to one another, and each elongated strip includes a titanium layer formed on the upper surface of the absorbing dielectric substrate and a gold layer formed on the titanium layer, such that the titanium layer is sandwiched between the gold layer and the upper surface of the absorbing dielectric substrate.