Browse Prior Art Database

Nematic Local Area Network Concentrator Switch

IP.com Disclosure Number: IPCOM000046484D
Original Publication Date: 1983-Jul-01
Included in the Prior Art Database: 2005-Feb-07
Document File: 2 page(s) / 57K

Publishing Venue

IBM

Related People

Palounek, LR: AUTHOR

Abstract

This article describes a nematic local area network concentrator switch which could be used in a local area network having a fiber-optic transmission medium. A nematic shutter within the switch is heated by injecting optical energy through the optical fiber which carries signals from a local terminal.

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Nematic Local Area Network Concentrator Switch

This article describes a nematic local area network concentrator switch which could be used in a local area network having a fiber-optic transmission medium. A nematic shutter within the switch is heated by injecting optical energy through the optical fiber which carries signals from a local terminal.

Referring to Fig. 1, the nematic concentrator switch 10 is con nected in a ring, loop or bus arrangement. An input fiber 12 carries data signals from an upstream nematic concentrator switch. Signals received from fiber 12 or a local terminal device 16 are passed on to a downstream nematic concentrator switch through an output fiber 14. The terminal 16 can receive incoming signals from the switch 10 through a fiber 18.

The output from terminal 16 to the switch 10 is provided through a fiber 20 terminated at a "Y". Two different types of signals can be applied to fiber 20 at the Y. Data signals developed within a terminal logic block 22 are used to drive a light source 24 which may be a light-emitting diode or injection laser. Switch- enabling signals generated in a bypass control circuit 26 are applied to a second light source 28.

The signal generated by source 28 would be a high energy optical signal for heating a nematic shutter within switch 10. Source 28 is driven by control circuit
26.

Referring to Fig. 2, input fiber 12 ends at a microlens 30 which distributes optical energy throughout cone-encompassing light-colle...