Abstract:
An optical fiber having a core surrounded by a cladding layer which has an index of refraction less than the index of refraction of the core characterized by a longitudinal side coupling zone being formed by a longitudinal opening extending through the cladding layer of the fiber to expose a portion of the core. The optical fiber of the invention is particularly useful in conjunction with a light sensitive detector and is useful in a mixer where more than one fiber are joined together either in a bundle or in a strip configuration. The fiber with the side coupling zone can be formed by drawing the fiber from a workpiece having a core or rod member surrounded by a sleeve member or layer which is provided with the opening or can be drawn from a molten material utilizing a double crucible in which the opening of the inner crucible is provided with at least one bulge extending to the edge of the opening of the outer crucible.
Abstract:
A branching element for a single mode light waveguide characterized by monomode guides extending from a semi-transmissive reflective layer that is inclined to the axis thereof and the branching light waveguide is a multimode light waveguide which is positioned to receive light reflected by the layer from one of the monomode guides. The device has a good coupling efficiency and can be manufactured by a cheap and simple process.
Abstract:
An output/input coupler for multi-mode glass fibers characterized by a substrate and a main line having a square cross section disposed on the substrate and having at least one branch line extending on said substrate therefrom with the branch line having a rectangular cross section smaller than the cross section of the main line and having one surface coplanar with the surface of the main line. The branch line may have the same thickness as the main line with a reduced width or may have both a reduced thickness and width. In one embodiment, the branch line extends as an arc and may terminate in an end line which has a square cross section equal to the cross section of the main line and extends at an angle to the main line. In another embodiment, the branch line extends rectilinearly and may terminate in an end line which extends parallel to the main line and has a square cross section equal to the square cross section of the main line. The coupler may be formed by stamping the coupler from a sheet of material or by using a photolithographic process to form the coupler from a layer of photosensitive material. If the coupler has branch lines with a thickness less than the thickness of the main line, the photolithographic process includes developing a first layer or foil of photosensitive material to form part of the main line and the branch line and then developing a second applied layer to produce the remaining portion of the main line.
Abstract:
A method for producing a light conductor structure having a pair of light conductors embedded in a substrate and electrodes arranged between and along the light conductors, which structure is particularly adapted for use as an electrically controllable coupler, characterized by providing a substrate of an electro-optical material having a c-axis parallel to one surface of the substrate and extending at right angles to the longitudinal axes of the later formed light electrodes, forming a layer of polycrystalline silicon in zones of the substrate, which lie adjacent to second zones of said one surface in which second zones the light conductors will be formed; applying a layer of diffusion material to the silicon layer and the second zones which are free of silicon; diffusing the diffusion material into the substrate by heating to an elevated temperature to form light conductors by increasing the index of refraction of the light conductor above the index of refraction of the remaining portions of the substrate; applying a layer of chrome to the light conductors and the diffusion material disposed on the layer of silicon; removing the silicon layer and the layers of diffusion material and chrome carried thereon; applying a positive-acting layer of photo-lacquer; exposing the photo-lacquer through the substrate with the chrome covering the light conductors acting as a mask; developing the photo-lacquer layer to remove the exposed portions and retaining the unexposed portions overlying the light conductors; applying a metal layer to form electrodes adjacent to the light conductors; removing the remaining portion of the photo-lacquer layer; and then etching away the chrome layer lying on the light conductors.
Abstract:
An integrated optical modulator for modulating optical signals in dielectric wave guides characterized by at least one wave guide being disposed on a surface of a substrate and having an upper surface separated from a second wave guide disposed thereon by a dielectric, low loss film. The substrate supports at least a pair of electrodes on either side of the one wave guide and at least one of the wave guides is of an electro-optical material so that an application of a potential on the electrodes changes the propagation characteristic or constant of the one wave guide. In one embodiment of the invention, only a pair of wave guides are utilized. In another embodiment of the invention, three wave guides are utilized and two of the wave guides are provided in spaced parallel arrangement and are either separated from an upper surface of the third wave guide by the film or are disposed beneath the third wave guide and separated therefrom by the film.