International Business Machines Corporation

George R Stilwell, Jr

Eugene S Schlig

Edward C Uberbacher

James S Kolodzey

Theodore Brian Vojnovich

Francis Edward Noel, Jr

Roger C Williams

Mitchell Levy Loeb

Robert C Lynch

Dennis H Kekas

James W Sylivant

Edward Earl Harbour

Robert L Walker

Robert D Munn

Andrew L Bahl

Charles A Williamson

Robert M Walsh

A laser source suitable for driving single mode and multimode fiber communication lines. The driver circuit includes a photo diode that, in multimode operation, responds to the laser light and causes the laser's output amplitude and wavelength to rapidly fluctuate thus producing the incoherent light required to drive multimode fiber. In single mode operation, the photo diode is disabled and the laser produces the requisite coherent light.

Dual fiber drive system

An interface circuit for connecting an electrical half-duplex system to an optical simplex system includes logic which permits keep-alive signals to be gated onto the transmitting simplex fiber when data is not being received on the half-duplex conductor. The interface circuit includes receive logic connected in parallel with the receive data path. The receive logic responds to predetermined bit patterns in the received data to control the receive and transmit data path connections. The interface circuit also includes transmit logic connected in parallel with the transmit data path. The transmit logic responds to bit patterns in the data on the transmit data path to selectively gate the output of a keep-alive oscillator onto the transmit simplex fiber.

Control circuit for half-duplex/simplex interface in communication system

Described are a technique and an apparatus for deskewing data transmitted via a dispersive medium such as a fiber optic link. The relative delays in arrival time for a plurality of bits, propagated in separate channels are measured. The relative delays are used to calculate the wavelength (.lambda.) of one channel and the zero dispersion wavelength (.lambda..sub.0) of the medium. The relative delays in arrival times for the remaining bits in a group of bits are predicted using the measured relative delays, the spacing (.delta.) between the transmitters and the calculated wavelengths. An adjustable delay for storing data bits is provided in each channel. The relative delays are used to deskew the individual bits.

Optical fiber system

A wavelength agile optical receiver can be used in an optical equivalent of an 'order wire' data communication system. The receiver includes an acousto-optic grating which can be tuned to deflect optical signals received at a particular wavelength by changing a drive signal produced by an acoustic transducer. A multi-wavelength optical signal is applied to the grating. Under 'order wire' or quiescent conditions, light at an order wire wavelength is deflected onto a split optical detector. A processor is employed to select control signals for a voltage-controlled oscillator which drives the acoustic transducer. The processor can cause the transducer output to be changed to provide deflection of optical energy at a selectable wavelength onto the detector.

Wavelength agile optical receiver

An optical fiber connector includes a ferrule with an interior splice chamber. A fiber stub is installed in the ferrule in a factory operation with one end in the splice chamber. The ferrule also includes permanent, opposed electrodes with tips at the walls of the splice chamber. To attach the connector to an optical cable in a field operation, a predetermined length of insulation is stripped from the end of the cable and the bare fiber is inserted into the splice chamber through a bore in the ferrule. Voltage is applied across the electrodes to create a plasma arc in the splice chamber. The plasma arc melts and fuses the adjacent ends of the cable fiber and fiber stub.

Optical fiber connector having integral electrodes for use in fusion

In a highly modular terminal, pluggable functional units communicate optically through a closed chamber. Some functional units are logically integrated into the terminal structure while being physically remote. In a supermarket system, bar code scanners and produce scales are examples of physically remote functional units. A circuit for interfacing the remote units to the closed chamber uses a broadcast/concentrator mode of operation. A single optical detector broadcasts the extant chamber signals to all of the remote functional units. Signals from the remote units are logically ORed or concentrated to provide a drive signal for a single optical emitter capable of injecting optical energy into the chamber.

Circuit for interfacing remote functional units to a terminal

A detachable fiber optic connector assembly consists of two major components, a cable terminator and a connector unit. The cable terminator includes a collar which is glued or crimped onto the cable jacket adjacent the stripped end of the cable and a cylindrical housing which is trapped on the cable by the collar. The connector unit includes a short length of permanently-retained fiber with one exposed end. This unit further includes a splice sleeve for receiving the stripped end of the cable fiber and the other end of the permanently-retained fiber. The cable terminator and the connector unit have latches, such as BNC components, for detachably coupling the connector unit to the cable terminator.

Detachable fiber optic connector assembly

A modular terminal comprising a frame, a data distribution chamber, a power distribution apparatus and plural functional units. The functional units are supported and oriented by the frame in such a way that each interconnects with the power distribution components. Functional units communicate via optical transmissions through the data distribution chamber. This allows a functional unit to be inserted, removed or moved from one frame location to another without special equipment or tools by unskilled personnel.

Pluggable terminal architecture

A solid state circuit, which serves as a twin simplex/half-duplex converter, includes a triple input NAND gate. The output of the NAND gate is connected directly to the outgoing simplex conductor. Signals on the incoming simplex conductor are applied to the three inputs of the NAND gate through separate signal paths which introduce different delays. One signal path introduces an intermediate delay before applying the incoming signal to the NAND gate in an inverted form. The half-duplex line is connected to this signal path. While incoming signals are applied to all three inputs to the NAND gate as well as to the half-duplex line, a lack of coincidence at the inputs prevents any incoming signal from passing through the converter to the outgoing simplex line.

Half-duplex/simplex digital signal converter

A light switch for controlling the transmission of optical energy through optical fibers includes a hollow, light-transmitting tube extending transversely across the end of at least one light transmitting fiber. The tube contains one or more masses of light diverting material in a matrix of light-transparent fluid. The masses of light diverting material may be reflective, refractive or absorbent. Means are provided for varying the pressure along the tube to shift the masses relative to the light transmitting fiber so as to divert or pass the light to receiving fibers.

Fiber optics light switch

A light pen detection and tracking scheme for detecting and tracking both 'on' and 'off' cells with a single cursor voltage waveform in an AC gas discharge display panel. The special cursor voltage waveform is applied to the panel during the sustain cycle, in either a line-by-line or binary scanning fashion, to momentarily fire both 'on' and 'off' cells so that they may be detected by the light pen without a loss of the memory state of the cells. A cross-hair cursor is automatically displayed at the pen position when the search scan is complete. Since both 'on' and 'off' cells are detected, the system can respond to pen motion by repeating the search to reacquire the pen, so that no special tracking strategy is needed.

Light pen detection and tracking with AC plasma display panel

Improved writing and erasing in AC gas discharge display panels is obtained by applying a special normalizing voltage waveform to cause the cells to be in a more standardized state, so that the applied writing and erasing pulses act to cause wall voltage changes which are less sensitive to the cell's recent history. The special normalizing waveform is applied adjacent to the erase pulse and/or to the write pulse and acts to fire the cells in a manner such that there is no loss in the memory state of the cells.

Writing and erasing in AC plasma displays

A nondestructive, transparent cursor for AC plasma displays may be superimposed electronically over a displayed image without regenerating the original image each time the cursor is moved. The cursor is displayed by means of a special cursor drive waveform which discharges both previously 'on' and 'off' cells which form the cursor but permits reversion of the cells to their original state when the cursor drive waveform is removed and the normal sustaining waveform is restored.

Growing community of inventors

Raleigh, NC, United States of America

George R Stilwell, Jr