Abstract: A method for forming a three gate optical coupler, operating on a beam splitting principle, or a five gate optical coupler characterized by providing a carrier block having a pair of marks to define a line of a parting plane, creating a continuous branching waveguide structure having a waveguide node located adjacent to the parting plane of the carrier block by a ion exchange method, parting the carrier block in the parting plane, polishing the parted surfaces and forming a light transmitting optical layer, such as a frequency selective filter layer on a polished surface, then rejoining the two parts with the waveguides aligned. The method is particularly useful in forming three gate and five gate frequency multiplexers/demultiplexers, which have a continuous light waveguide structure except in the location of the frequency selective filter layer.

Abstract: A light branching element or diplexer comprising a first bi-directional light connection and a second and third unidirectional light connection. The unit is formed by a block having a straight surface groove with an embedded glass fiber which fiber is interrupted by a partially transmissive mirror lying on a slanting plane relative to the axis of the fiber. The light sensitive location of a light receiving semiconductor element is secured to the block adjacent to the mirror and the plane of the mirror is selected so that its normal extends out of the block at an angle of incidence smaller than 45.degree. to the axis of the fiber to reduce reflections from the semiconductor member back to the mirror and into the fiber.

Abstract: An edge interference filter is composed of a layer sequence of a total of 21 alternately arranged high refractive index layers and low refractive index layers with the high refractive index layers being composed of TiO.sub.2 and the low refractive index layers being composed of SiO.sub.2. The individual layers having an optical layer thickness standardized to a 20.degree. angle of incidence and to 3/4 wavelength of the attenuation band center wavelength of 823 nm with the first and twentyfirst layers having a thickness of 0.241 of the standardized thickness, the second and twentieth layers having a thickness of 0.914 of the standardized thickness and the remaining third through nineteenth layers having a thickness of one standardized thickness.

Abstract: A multiplex-demultiplex module having a laser diode and a strip waveguide leading from said laser diode being disposed on a first surface of a substrate and the waveguide extends to an out-coupling and in-coupling location characterized by a single combined grating being arranged on the first surface of the substrate having its grid lines extending perpendicular to the direction of radiation guided in the waveguide and dimensioned so that it will not influence the laser emissions of a first wavelength from the laser diode but will steer radiation supplied from an in-coupling location and having a second wavelength differing from the first wavelength through the substrate onto a photo diode located under the opposite surface of the substrate. The grating thus acts as both a frequency-selective and a diffracting grating and replaces the two gratings in previously known devices.

Abstract: A monolithically integrated WDM demultiplex module has a film wave guide of InGaAsP fashioned on a substrate, a photodiode of InGaAs being applied to the film wave guide. The photodiode is optically coupled to the film wave guide by a leakage coupling. A wavelength selection element in the form of a grating is provided in the surface of the film wave guide. The module can be manufactured with a single epitaxial step. Structures for increasing the crosstalk attenuation of the module and for a better coupling-in of radiation into the module are provided.

Abstract: An optical device for use either as a waveguide demultiplexer or a waveguide multiplexer characterized by a compact transparent member having a surface forming optical means such as an imaging mirror, an opposite surface portion having a diffraction grating formed thereon and first and second coupling surfaces so that light can be coupled into the member reflected by the mirror and the diffraction grating and then coupled out of the member. The device has various embodiments with different structures for the optical mirror and the transparent member, with the structure of the coupling surfaces being flat or curved, and with either flat or curved additional mirrors for reflecting the incoming and outgoing light adjacent to the coupling surfaces.

Abstract: An edge interference filter transmitting short-wave for great interchannel spacing of about 200 nm given an attenuation band wavelength of about 1300 nm. The filter is composed of a layer sequence of a total of 23 alternately high and low refractive index layers wherein the high index of refraction layers have an index of refraction of 2.08 and the low index of refraction layers have an index of approximately 1.45, the effective optical layer thickness of the individual layers is standardized to a 20.degree. angle of incidence and to 1/4 wavelength of the attenuation band center wavelength of 1260 nm with to layers 1 and 23 having a thickness of 1.146, layers 2 and 22 having a thickness of 0.909, layers 3 and 21 having a thickness of 1.039, layers 4 and 20 having a thickness of 0.932 and layers 5-19 having a thickness of 1.

Abstract: An optical waveguide junction which can be used as a wavelength demultiplexer, having two aligned fibers separated from each other by a wavelength-selective filter and a fiber branching off laterally from these fibers at the level of the filter. At the same time, a greater degree of coupling efficiency, applicability in monomode fiber lines, and greater adjusting tolerances in production of the junction are achieved. It is recommended that each of the two aligned fibers have different core diameters, while the fiber feeding the filter has a smaller core diameter than the fiber continuing from the filter. In one embodiment of the invention the feed fiber includes a monomode fiber and the continuing fiber of a multimode. The junction can be used as a demultiplexer for optical-fiber transmission lines for unidirectional operation for demultiplexing.

Abstract: A method for integrating a DFB laser and a passive strip waveguide on a substrate. A layer stack is produced in a first epitaxy step, the layer stack having a laser-active layer and a surface-wide grating on the uppermost layer, and eroding the stack area-wise, but only down to a layer under the laser-active layer, not down to the substrate, by means of etching to create a step separating the laser region from the passive strip waveguide region. By employing an etching stop layer, the etching can ensue self-adjustingly, and the coupling between the laser-active layer and the passive strip waveguide region occurs not by end coupling, but by surface coupling. Only two epitaxy steps are required for the complete manufacture of the structure, and a strip required for the definition of the laser and of the waveguide can be produced in the same single method step.

Abstract: A branch connector for light waveguides which utilizes a beam divider mirror characterized by a carrier member aligning a pair of light waveguides on a common axis, a beam divider which is arranged on a plane slanted to the common axis on an angle which is larger than 45 degrees and is positioned between the ends of the waveguides and flush therewith and a second carrier plate mounting an additional waveguide adjacent one of the pair of aligned waveguides on a second axis extending at an angle to the common axis and intersecting the common axis at the beam divider mirror with the second axis being oriented to receive light reflected along the given direction.

Abstract: An optical cut-off filter characterized by a multi-layer system comprising of a sequence of dielectric layers which are bordered on each side by a transparent medium having an equal or same index of refraction with the index of refraction of each of the dielectric layers being selected so that for a preselected radiation angle of incidence, the band paths of the filter have an envelope of reflected secondary maximum for a component vibrating perpendicular to the radiation plane of incidence and the envelope for a component vibrating parallel to the radiation of planar incidence of the electrical field vector of incident radiation, and both envelopes exhibit zero locations which have a different wavelength due to the selection of the index of refraction of the dielectric layers forming the filter.

Abstract: A branch component and method of making the component which can be used either to distribute light from a single waveguide into four outgoing waveguides or to collect light from four incoming waveguides into a single outgoing waveguide.

Abstract: A coupling device for coupling two waveguides having different cross sections, for example a layer conductor or laser element to a strip conductor, characterized by a telescopic system, which narrows the beam cross section of the larger of these two waveguides and directs it onto a large cross-sectional end of a tapering waveguide, which tapers down to the cross section of the other waveguide or conductor. The telescopic system can be composed of one conical gradient lens, two coaxial gradient lenses, or a gradient lens coaxially arranged with a conical gradient lens. The tapering waveguide preferably is integral with the strip waveguide or conductor and is of the same type.

Abstract: A liquid crystal cell comprising a layer of liquid crystal material interposed between a pair of carrier plates with at least one plate being transparent characterized by a film of metal inorganic salt selected from a group comprising magnesium fluoride, thorium fluoride, zinc sulphide, aluminum oxide, or thorium oxide deposited on at least selected areas of a surface of one of the carrier plates to cause homeotropic orientation or a tilted homeotropic orientation of the molecules of the liquid crystal material contacting the film. To provide the film, the carrier plate is positioned in spaced relationship to a source of the salt which is vaporized and deposited on the plate in the desired areas to produce the column-like structure of the desired angular orientation.