Showing papers on "Optical switch published in 1983"

Optical switch, and a matrix of such switches

Abstract: A light ray (6) passes through a light-passing region of a transparent wall (1). Adjacent to said light passing region there is a wettable drop-receiving region (4,5) with a liquid (7,8) thereon. A moving member (11,12) has a rest position in which the liquid is free to occupy only the wettable drop-receiving region, and a working position in which it moves at least a portion of the liquid onto the light-passing region, thereby modifying the light ray (6). Various kinds of switches, such as an on/off switch or a deflector switch, can be devised by suitable choice of the liquid (e.g. its refractive index, or its reflecting properties), and the angle of incidence of the light ray (6). The moving member may be controlled electromagnetically.

Proposal of Electro-Optical Switching and Memory Devices Utilizing Doping and Undoping Processes of Conducting Polymers

Abstract: New optical switching and memory elements utilizing the spectral change of conducting polymers by electro-chemical doping and undoping are proposed.

Electro-optical switch for unpolarized optical signals

Abstract: An optical 1×N switch uses a polarizing beam splitter cube and a reflector to separate an arbitrarily polarized incident light beam into polarized components which propagate along parallel paths. A polarization rotator is positioned in the path of the reflected component to rotate the plane of polarization of the light beam component propagating therealong to be coplanar with that of the undeviated light beam in the parallel path. The two beams are simultaneously or individually deflected by selectively activating the electrodes of a liquid crystal nematic reflector/transmitter array confined between prismatic bodies to emerge at one or more of a plurality of desired outputs. In a second embodiment, a second polarization rotator and polarizing beam combiner assembly re-establishes the initial polarization and the beams are thereby combined to emerge from one or more selected output terminals as an arbitrarily polarized light beam. The switch exhibits extremely low crosstalk and insertion loss by utilizing the energy of both parallel and normal incidence polarization components and avoiding propagation of undesired stray polarization components as occurs with a liquid crystal polarizer.

Electrowetting switch for multimode optical fibers

Abstract: Construction and characterization of an optical switch, based on electrowetting and suitable for use with multimode fibers are described. With a 50-μm core, 0.23-N.A. input and output fibers, the measured fiber-to-fiber insertion loss at λ = 0.633 μm was 0.5 ± 0.1 dB for one channel and 2.0 ± 0.2 dB for the other, with cross talk of −22.8 ± 0.5 and <−51 dB, respectively. Response time is ≈20 msec with driving power of ≈25 μW and a voltage requirement of ≤1.0 V. The switch has been tested for over 107 cycles with no observable degradation.

Optical matrix switch

Abstract: An m×n optical switch is formed on a semiconductor substrate. Grooves are etched at the edges of the substrate to accommodate input and output optical fibers so that the output fibers are placed orthogonal to the light paths of the input fibers. An array of photodetectors is provided at an edge opposite to that of the input fibers to receive the input signals. At each crosspoint defined by the input and output fibers is an electromechanically actuated mirror which in one state permits passage of light from its associated input fiber, and in another state deflects the light to its associated output fiber.

Bulk/interactive data switching system.

Abstract: Data communications connections between interactive terminals (T11) and host computers generally exhibit long holding times, while the data density of the transmission is sparse. The circuit switch (101) of a switching system is an inefficient and expensive medium for this type of communication. Thus, the subject switching system uses a packet switch (106) connected in parallel with the circuit switch (101) to handle bursty data traffic from interactive terminals (T11). A routing bit (Fig. 6) is set in the data stream from each port circuit (111) to indicate the nature of the transmission and this transmission is then routed to the packet switch (106) if it is a bursty data transmission while voice messages are routed to the circuit switch (101).

Optical switch of switched directional coupler type

Abstract: An optical switch with switched optical directional couplers, switched by the application of either 0 volt or a voltage V 1 , different from 0 volt. Coupling of almost 100% is achieved when the V 1 voltage is applied to a selected directional coupler, while coupling of 0% to 20% occurs when 0 volt is applied to the selected directional coupler. The optical directional coupler is formed by locating adjacent optical waveguides in close proximity and applying electric field producing electrodes to the waveguides where they are in close proximity such that the substrate below opposing waveguide sections receive electric fields of opposite directions.

High-speed traveling-wave directional coupler switch/modulator for &#955; = 1.32 &#181;m

Abstract: We have designed and fabricated a Ti:LiNbO 3 waveguide traveling-wave directional coupler switch/modulator operating at \lambda = 1.32 \mu m that exhibits a 3 dB modulation bandwidth of 7.2 GHz, a switching voltage of 4.5 V, and power per unit bandwidth of 7.6 mw/ GHz. Using short drive pulses, optical pulsewidths as short as 58 ps have been generated and directly measured with a high-speed InGaAs/InP p-i-n photodiode. Thick ( \sim 2.8 \mu m) electroplated gold has been used to produce a small gap (5 μm) and low-loss coplanar strip electrode. The 1.5 cm long, 15 μm wide electrode has a dc resistance of 7 Ω and a total microwave power loss of ∼4dB at 5 GHz.

Solar optical materials for innovative window design

Abstract: New and innovative optical materials and coatings can greatly improve the efficiency of window energy systems. These potential materials and coatings increase energy efficiency by reducing radiative losses in the infrared, or reducing visible reflection losses or controlling overheating due to solar gain. Current progress in heat mirror coatings for glass a polymeric substrates is presented. Highly doped semiconducting oxides and metal/dielectric interference coatings are reviewed. Physical and optical properties are outlined for antireflection films and transparent aerogel insulation media. The potential for optical switching films as window elements includes discussions of electrochromic, photochromic and other physical switching processes.

Optical device with surface plasmons

Abstract: An optical device used as an optical switch or bistable device, with surface plasmons, is comprised of a semiconductor base material forming a non-linear dielectric layer along with a metal layer, with an interface between the metal and semiconductor layers including a submicron grating. The device is optically excited from a light source of given intensity. In accordance with the invention, dispersion relation of surface plasmons may be changed by varying the intensity of an input laser so as to provide bistable or hysteresis effect switching. The concepts of the invention may be implemented in either an unadorned device as set forth, or may be fabricated in an optical waveguide.

A new Faraday rotator using a thick Gd:YIG film grown by liquid-phase epitaxy and its applications to an optical isolator and optical switch

Abstract: A new Faraday rotator using a thick garnet film grown by liquid-phase epitaxy (LPE) has been proposed and film growth technology for the rotator has been investigated. The new Faraday rotator had good features of very low cost and small size, due to high productivity of the LPE-grown film and low magnetic saturation field, respectively. By using the new Faraday rotator, an optical isolator and magnetooptic switch for single-mode fiber systems have been developed. The optical isolator featured 0.8-dB insertion loss and 25-dB isolation at 1.3-μm wavelength. The magneto-optic 1 × 2 switch was independent of light polarization and featured 1.3-1.7-dB insertion loss, -25-dB crosstalk, and 30-μs switching time at 1.3-μm wavelength. Minimum switching voltage was ±5 V. Magneto-optic devices using the new Faraday rotator is practical for use in 1.2-1.7-\mu m wavelength fiber-optic systems, because of good optical properties, compactness, and low cost.

Optical fiber joint type ion-concentration measurement apparatus

Abstract: An optical fiber joint type ion-concentration measurement apparatus in which electrical signals which are detected by an ion selective electrode are transformed into optical signals which are transmitted to a receiving side of the apparatus by means of optical fibers. The detected signals from the electrode are frequency modulated by a voltage/frequency converter and the output of the voltage/frequency converter is used to control an electronic switch. The electronic switch controls a series circuit including a power source and a charging-discharging capacitor and a light emitting diode. The frequency modulated transformed detected signals therefore cause the light emitting diode to emit optical signals which are then transmitted by means of optical fibers. On the receiving end of the apparatus, the optical signals are transformed into electrical signals by a photo diode and then demodulated by a frequency/voltage converter to reproduce the original detected signals from the ion selective electrode.

High speed optically controlled sampling system

Abstract: A number of high frequency signal sources such as a number of receiving annas have their information content extracted by an optoelectronic synchronous sampling system. A laser provides pulses of proper frequency and duration and feeds them to a fiberoptic bundle. In one embodiment the fibers are lengthened to be simultaneously actuated. Otherwise, each of the fibers in the bundle has a different length so that light emanating from their distal ends appears as a delayed series of actuating light pulses. Phase shifters, pressure or electric field effects, can effect delay and consequent beamforming. Optoelectronic switches are disposed adjacent the distal ends so that the delayed series of actuating pulses actuates the switches in a synchronous sequence to synchronously sample the high frequency signals received by each of the antennas. Interconnected analog-to-digtal and processing circuitry conditions the synchronously received samples for further use. The discrete delays assured by the different lengths of the optical fibers and the optoelectronic switches enable responsive synchronous sampling of the number of high frequency sources to extract their information content. There is no EMI or RFI, neither does it generate them. This can effectively operate in a high noise environment.

Electrooptical branching waveguide switches and their application to 1 &#215; 4 optical switching networks

Abstract: This paper presents design considerations and experimental results of single-mode branching waveguide switches in LiNbO 3 for the application to optical switching networks. The extinction ratios of 15 and 25 dB were obtained for symmetric and asymmetric structures, respectively. The experimental results are in good agreement with the theoretical ones. 1 × 4 optical switching networks using the branching waveguide switches are also demonstrated.

Electro-optic switching system using circularly polarized light

Abstract: A method and an apparatus provide an optical switching system (100) which maintains essentially constant transmissivity at its maximum value and develops independent of viewing angle two system optical transmission states of substantially contaminant-free light. The system includes first and second light gates (102 and 104) of which each has associated therewith contaminant light intensity patterns (48 and 66) with points of local maxima (54, 56, 58, 60, 68, and 70) and local minima (62 and 72) in two system optical transmission states. Quarter-wave plates (134 and 136) are positioned between the light gates to develop circular polarization of light propagating between them. The presence of circularly polarized light maintains the system transmissivity at its maximum value while the relative orientation of the light gates is changed to align their contaminant light intensity patterns to block the transmission of contaminant light, and thereby improve the viewing angle performance.

Optical time-division switching system employing optical bistable devices

Abstract: In an optical time-division switching system, time-division multiplexed calling and called station signals are arranged in incoming time slots and applied through an incoming common optical medium to a first optical switching circuit that switches the signals to optical bistable devices in which the signals are stored as binary 1's or 0's. A second optical switching circuit is coupled to the bistable devices for reading the stored calling station signal in the time slot of the called station and reading the stored called station signal in the time slot of the calling station to rearrange the signals in outgoing time slots. The signals in the outgoing time slots are applied through an outgoing common optical medium to a time-division demultiplexer which sequentially distributes the signals to the calling and called stations.

Optical matrix switch

Abstract: PURPOSE:To eliminate the delay of a switching time required for an arithmetic processing and to prevent the leading of wiring from being increased, by replying a discrimination and control circuit to each of a unit optical switch, and arranging the circuit in the neighborhood of the switch, in an optical matrix switch consisting of the discrimination and control circuit which controls the unit optical switch. CONSTITUTION:A light signal having an address signal at the beginning is inputted to an input light terminal. The inputted light signal is inputted to optical switches 5 and 6 by a light branch coupler circuit 8. The switch generates an electromotive force between terminals when a beam of light is inputted to an activating layer similarly as a photodiode. Therefore, by designing the discrimination and control circuit 7 so that the optical switch 5 of a unit at a k-th stage can be turned on when the k-th pulse of the address signal is set at '1', and an optical switch 6 is turned off, and a reverse operation is performed when it is set at '0', input can be performed by adding an address pulse of 1110000 on the signal to pass the optical signal from the input to an output. Such address discrimination can be performed simply, and quite a few time is required for discrimination. Also, since the discrimination and control circuit is arranged in the neighborhood of each unit, wiring can be performed in short length.

Picosecond bistable optical switch using two-photon transitions

Abstract: A bistable optical switch comprising a Fabry-Perot resonator containing a nonlinear semiconductor medium with a desired band structure and whose susceptibility (refractive index) varies with optical energy density. The Fabry-Perot resonator is biased to a point where two stable transmission states are possible. Switching is accomplished by pumping the nonlinear material with an energy hw in the range 1/2Δ g

Digital and analog optical broad-band transmission

Abstract: The paper describes several experimental digital and analog optical broad-band transmission systems and characterizes the problems which had to be solved to realize these systems. The experiences gained are described and discussed with respect to the future development of digital and analog optical broad-band transmission technique.

Optical switching system

Abstract: An optical switching system is disclosed comprising a set of optical hardware operating on control status supplied from electronic or electromechanical devices connected in a communication network to connect subscribing devices in the network for data transfer, wherein both control information for the system and the actual data information to be passed between two connected devices are coded in position coded light spots, and carried to the switching system by optical fibers.

Circuit arrangement for conversion TTL logic signals to ECL logic signals

Abstract: A circuit arrangement for level conversion of TTL-logic levels to ECL-logic levels with at least one emitter-coupled current switch having an input addressable by TTL-logic levels and an output from which ECL-logic levels can be taken off, including a first current switch formed of two emitter-coupled npn-transistors (and a second current switch formed of two emitter-coupled pnp-transistors, one of the transistors of the second current switch being arranged as input stage for the first current switch, the second current switch having a switching threshold higher than that of the first current switch.

Switch debounce circuit

Abstract: A circuit for eliminating transient pulses generated by bouncing mechanical contacts within a switch. A shift register accepts a series of binary input signals from the switch and propagates the signal out the register in parallel to a logic device for generating a resultant binary signal corresponding to the switch's debounced signal state.

Bipolar voltage controlled optical switch using intersecting waveguide

Abstract: An optical switch comprises a substrate 1, 1', a waveguide 2,3, 21, a pair of input 2, 3, 22, 23, and a pair of output waveguides 2, 3, 24, 25. The refractive index of a part of the waveguide 4', 41, 42, is changed to effect switchin of a light beam from one path to another through the waveguide. The part of the waveguide the refractive index of which is changed is narrower than the remainder of the waveguide and is centrally symmetrical with respect to the waveguide.

Optical switching device

Abstract: An arbitrary number of outgoing optical fibres can be coupled in a constant optical path to an incoming optical fibre which is connected to a deflecting system and is carried along therewith. The deflecting system can be displaced longitudinally in the direction of the axis of the incoming optical fibre and can be positioned with respect to one of the juxtaposed outgoing optical fibres.

Fiberoptic switch system

Abstract: A fiberoptic limit switch system comprising a light source, an optical beamsplitting arrangement, a switch, an optical fiber, a detector, and output circuitry. The light source is a light-emitting diode. The switch is responsive to external stimulus. The switch comprises a housing, a receptacle for receiving the optical fiber, and a reflective surface movable between two positions within the housing. The optical fiber extends from the light source to the switch. The detector is arranged so as to receive light from the optical fiber and transmit a signal relative to the light emission. The output circuitry is electrically connected to the detector.

Fibre-optic coupling arrangement

Abstract: The object of the invention is an optical component which consists of an optical fibre and a (fibre-optic) graded-index rod lens, which is coupled thereto and whose other end surface is inclined relative to the optical axis. Such a component can be used in manifold ways, e.g. in multiplexers, splitters, optical filters and optical switches.

rf Switching apparatus utilizing optical control signals to reduce spurious output

Abstract: An rf multiplexer includes a plurality of rf switch assemblies for switching a selected rf signal to an output in response to an optical control signal. Each rf switch assembly includes a switch circuit mounted in a conductive enclosure. The optical control signal from a control circuit is coupled by an optical fiber into the enclosure to an optical receiver which energizes a diode rf switch. Spurious conduction of rf signals along switch control lines is thereby eliminated without using filters. The multiplexer is particularly useful in a direct frequency synthesizer requiring high speed switching.

Space optical modulating and demodulating device

Abstract: PURPOSE:To attain the miniaturization as well as a simultaneous optical communication with just a single light source by unifying a corner cube, an optical demodulator and an optical modulator. CONSTITUTION:An optical modulator 1 modulates the light beams of a laser 2 with an information signal 3 and irradiates these modulated beams to a corner cube 4. A semi-transparent reflecting plate is provided to the cube 4 together with a photoelectric transducer attached to the rear side of the cube 4. Thus an optical demodulator 5 is obtained. In such a way, a part of the incident light is supplied to a signal processing circuit 6 after photoelectric conversion and demodulation. While the reflected light sent from the reflecting plate is reflected again by a reflecting plate set at the same cube 4. A modulator element made of a material having an electro-optical effect and containing an optical switch function is provided at the front of the reflecting plate. Thus an optical modulator 8 is formed. Thus the reflected light is modulated with an information signal 7 and reflected in parallel to the incident light. This reflected light is sent to an optical demodulator 9 to receive photoelectric conversion and then supplied to a signal processing circuit 10 after demodulation.

Waveguide polarization regulator

Abstract: PURPOSE:To obtain a polarization regulator capble of converting incident light in any polarization state into a specific polarized component on the same substrate as an optical switch without adjustment, by occluding a light wave in an optical waveguide provided on the substrate and then adjusting it electrically through electrooptic effect. CONSTITUTION:Incident light 8 from an optical fiber has both modes TE and TM when entering an optical waveguide 1 in the form of an elliptic polarized light. Because of a metallic film on an optical waveguide 2, the propagation constant of the mode TM is greatly different between the optical waveguides 1 and 2, or nearly equal in mode TE, so only the mode Te is coupled with the optical waveguide 2 while the mode TM is coupled with a branch coupling optical waveguide 5. A voltage is applied between electrodes 6 and 7 and electrode periods compensate the phase difference between TE and TM in an optical waveguide 4, so the mode TM incident from the optical waveguide 2 to the optical waveguide 4 changes into the mode TM to propagate to an optical waveguide 5, thereby emitting TE mode light from the waveguide 5 without reference to the polarization state of the incident light 8.

Photoconductive Pulse Power Switches

Abstract: : This paper outlines the advantages and the potential of photoconductive switches applied to pulse power systems. The photoconductive effect can be used to switch large amounts of energy by changing the conductivity of a solid-state circuit element many orders of magnitude with a high-power laser. The simplicity of these devices offers many advantages in pulse power applications when combined with high-power pulsed lasers. The surge capability, the switched energy gain, and the maximum average power for photoconductive power switches are discussed. In addition, the results of a 100-kV, 100-MW photoconductive switch experiment transferring 20 J in 200 ns are presented.