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Gigabit Binary Optical Data Link

IP.com Disclosure Number: IPCOM000092750D
Original Publication Date: 1967-Jan-01
Included in the Prior Art Database: 2005-Mar-05
Document File: 2 page(s) / 30K

Publishing Venue

IBM

Related People

Smith, AW: AUTHOR [+2]

Abstract

This technique is for amplitude modulating a laser beam in a binary mode, i.e., on or off condition, at a rate of the order of 109 bits/sec. The high-speed data transmission is achieved mainly by the use of the electro-optic effect in bulk gallium arsenide GaAs due to the high electric field present in moving domains of electric field, the Gunn Effect. Such is also particularly due to that property of the Gunn Effect in which a domain can be launched by a voltage pulse and supported by a lower than threshold bias voltage.

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Gigabit Binary Optical Data Link

This technique is for amplitude modulating a laser beam in a binary mode,
i.e., on or off condition, at a rate of the order of 109 bits/sec. The high-speed data transmission is achieved mainly by the use of the electro-optic effect in bulk gallium arsenide GaAs due to the high electric field present in moving domains of electric field, the Gunn Effect. Such is also particularly due to that property of the Gunn Effect in which a domain can be launched by a voltage pulse and supported by a lower than threshold bias voltage.

Gunn and others show that under certain conditions a high field domain is formed when an applied electric field exceeds some threshold value, propagates toward the positive electrode, and periodically disappears and re-nucleates. The peak electric field in the moving domain is not known exactly, but depending on material resistivity, length of device, homogeneity of crystal, etc., is of the order of 50-100 Kv/cm, as contrasted to the field outside the domain which is only several thousand V/cm. Since the electro-optic effect in GaAs is large, the induced birefringence when the domain is present is large enough to be detectable.

The high-speed data transmission device comprises a source of laser light source 2, polarizer 4, lens 6 for focusing laser beam 8 onto a GaAs Gunn oscillator 10. The second polarizer 14 is added to obtain amplitude modulation. Lens 12 recollimates the light. Light detector 16 comprises the sensing portions of the data transmission system. Battery...