Abstract: A switch mechanism for switching signals at inputs onto outputs and switching networks for interlinking first and second transmission media. Switching networks for interlinking first and second transmission media for the transmission of signals in frequency-division or space-division multiplex have a substantially simpler architecture in comparison to known switching networks. To that end, the switching networks are constructed with a new switch mechanism composed of a plurality of adjustable frequency converters of the input side, of a means for distributing the signals and of doubly adjustable frequency converters of the output side and/or of a plurality of doubly adjustable frequency converters of the input side, a means for distributing the signals and adjustable frequency converters of the output side. A simpler structure can be achieved in a known switching network of the Clos type in that shared-medium switches of two different types are employed.

Abstract: In an asychronously operating optical data bus:(a) data collisions are detected via two analog comparators by amplitude evaluation if the input optical power fluctuations at the site of a receiver as a function of all transmitters do not exceed approximately 3 dB; or(b) at first only one or more transmitting subscribers detect collisions and communicate this to other subscribers by one or more JAM signals; or(c) each subscriber interrogates, during the time which corresponds to its bus turn-around time, whether in its receiver, data signals are arriving from the bus.

Abstract: An optical data bus with a statistical access method for the transmission of data between transmitters and receivers in the form of NRZ data provides that every transmitter of a subscriber contains a Manchester encoder which Manchester encodes the NRZ data and deposits such data onto the bus in a Manchester-encoded form. The receiver of every subscriber contains a Manchester decoder for the reacquisition of the NRZ data from the Manchester encoded data and contains a clock recovery device which recovers the clock contained in the Manchester-encoded data. Such a Manchester decoder with the clock recovery device can be constructed in a very simple manner and such a simple structure is disclosed. A very simply-constructed bus state recognition device is also included.

Abstract: A method and outage recognition device for use with a redundantly designed optical transmission system having at least two receiver circuits at each station of the system with each receiver circuit having an input, an output and a separate transmission channel connected to the input characterized by the recognition device and method determining an outage of either one of the transmission channels by applying an output of each of the receiver circuits to a means for recognizing outages in the channel and determining the outage in the transmission channel by the occurrent data independent of statistical phase positions of the data in each channel. In a specific embodiment of the device, various logic elements are interconnected in a manner so that they not only reliably identify an outage of a channel but also indicate which channel has failed.

Abstract: A device for recovery of a synchronized clock signal from a signal sequence, in particular a random sequence, clocked at a specific frequency. The device includes a clock generator which by itself generates clock signals whose phase and frequency are tuned to the specific phase and clock frequency of the signal sequence, and which is triggerable externally by specific signals derived from the signal sequence in order to synchronize its phase and frequency with the phase and clock frequency of the signal sequence. The clock generator includes preferably a monostable multivibrator whose output signals are fed back delayed to the input serving as trigger input.

Abstract: If data from more than one subscriber circulates on a bus link in an optical bus network structure in which access of the subscribers to the bus is not synchronously controlled, data collisions can occur. In order to guarantee a high data throughput on the bus, these data collisions must be avoided insofar as possible or must be quickly perceived. A circuit for identifying possible data collisions determines whether the bus is free for a subscriber wishing to transmit, and which permits collisions on the bus to be quickly identified and corresponding measures to be quickly initiated to prevent further collisions. The present invention enables a subscriber to a bus system to distinguish between a data collision and normal transmission errors. This distinction is made by concluding that a collision has occurred only when the bit error frequency is substantially higher than the probabilistically determined normal transmission error frequency.

Abstract: An optical star coupler for use in optical systems with multi-mode optical fibers for interconnecting two groups of system fibers, characterized by the star coupler comprising a mixing element, two groups of optical fiber elements and an arrangement for positioning the mixing element and the groups of fiber elements in the same plane. The mixing element is a planar waveguide which has an input and output end which are interconnected to groups of the fiber elements with a packing density of each group of the fiber elements at the input and output ends being as high as possible. The planar waveguide has a thickness approximately equal to the diameter of the fiber elements and the diameter of each of the fiber elements is approximately equal to the core diameter of the system fiber to which it is connected and all of the fiber elements are selected to be of one type of fiber which are either gradient fibers or stepped profile fibers.

Abstract: A coupler which is used with light conducting system fibers of a fiber optical communication system to couple-out and couple-in a light signal to the system fibers characterized by the coupler having at least three optical coupler fibers for connection to the system fibers and an arrangement for holding the fibers in a plane with two of the fibers converging together to have a portion of each of the fibers adjacent the end face in parallel side by side relationship with the end faces being flush and holding at least the third fiber with its end face abutting against the end faces of the pair of fibers with each of the glass fibers forming the coupler having an overall diameter which is equal to the core diameter of the system fibers which are connected thereto. Preferably, the cladding of each of the coupler fibers is as thin as possible and the coupling fibers may be embedded in a material having an index of refraction which is less than that of the cladding of the fiber to reduce light losses.

Abstract: Method and apparatus for an optical four-gate coupler wherein the junction between two large fiber optical waveguides of the same diameter are connected to a fiber optical waveguide having a smaller diameter and wherein a guide part is formed with a groove for engaging the small fiber optical waveguide and the distance from the center line of said groove to the edge of the guide is equal to the diameter of the larger waveguides so that the guide part and a detent can hold the two large waveguides and the smaller waveguide in aligned contacting positions and a cover plate fits over at least the two large waveguides. Such structure is then cut transverse to the center axis of the three waveguides and the ends are polished and then coupled together so as to provide an optical four-gate coupler.

Abstract: A three dimensional star coupler for interconnecting a first bunch of optical waveguides such as fibers to a second bunch of optical waveguides or optical fibers characterized by a mixing element being a planar waveguide having a thickness approximately equal to the fiber diameter and having input and output surfaces coupled to the incoming and outgoing fibers which are all supported in the same plane. The mixing element consists for example of an elongated rectangular plate but also can have a configuration of arcs of a circular configuration.

Abstract: A light distributor which is connected to an incoming light guide and a plurality of outgoing light guides for distributing a light arriving from the incoming light guide into the plurality of outgoing light guides characterized by the distributor comprising a disk member, which may be circular, of a material which has properties of a low absorption and low scattering, and the member has an abutting surface for both the incoming and outgoing light guides with the abutting surface of the incoming light guide being opposite to the abutting surface of the outgoing light guides. The disk member of the light distributor will have a thickness equivalent to the diameter of the cores of the light guides. The disk member may be of a material which is birefringent or which has a controllable index of refraction.