Browse Prior Art Database

Integrated Bidirectional Fiber Optic Repeater

IP.com Disclosure Number: IPCOM000052064D
Original Publication Date: 1981-Apr-01
Included in the Prior Art Database: 2005-Feb-11
Document File: 2 page(s) / 43K

Publishing Venue

IBM

Related People

Bachtold, W: AUTHOR [+2]

Abstract

For optical fiber communication systems a repeater is built as an integrated device structure. For example, on a substrate there are vertically combined a first laser and a first photodiode, a second laser and a second photodiode. On top there are field-effect transistors. The sandwich structure is directly coupled to optical fibers.

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Integrated Bidirectional Fiber Optic Repeater

For optical fiber communication systems a repeater is built as an integrated device structure. For example, on a substrate there are vertically combined a first laser and a first photodiode, a second laser and a second photodiode. On top there are field-effect transistors. The sandwich structure is directly coupled to optical fibers.

The first laser-diode set is matched to a first low-loss window of the optical fiber used, say, to a wavelength of 1.30 mu m. The second laser-diode set is matched to a wavelength of 1.55 mu m. For bidirectional communication either wavelength range is used for a different direction.

The fabrication technique is preferably multilayer liquid-phase epitaxy. On an InP substrate of [100] orientation a first multilayer is grown to achieve the faceting transition and thus extremely flat surfaces. All epitaxial layers for the device structures are grown on the faceted substrate and thus are equally flat.

The example shown comprises a sequence of 20 layers. The first five layers serve to develop the facet and to reduce the dislocation density. The next 13 layers build both sets of devices. Both diode lasers contain a (hatched) intrinsic layer of about 0.04 to 0.1 mu m thickness between their p and n regions. On top of the devices the upper hatched layer indicates an insulating intrinsic InP layer separating the electrooptic devices from the MESFETs. Their channel layer is built of an n-InP:Te lay...