Lucent Technologies Inc.

At&t Bell Laboratories

James Dennis Wynn

George J Zydzik

Man Fei Yan

Utpal Kumar Chakrabarti

Lucian Arthur D'Asaro

Leo M Chirovsky

Sanghee Park Hui

Patrick William Wisk

Daryoosh Vakhshoori

William Scott Hobson

Betty Jyue Tseng

Ronald Eugene Leibenguth

Judith Francavilla De Jong

Erdmann Frederick Schubert

The specification describes a process and apparatus for collapsing preform tubes in Modified Chemical Vapor Deposition processes. The problem of bubble formation during tube collapse was found to be attributable to excess dopant vapor pressure emitted from the hot zone during the final stage of tube collapse. This excess pressure is controlled by cooling the tube in advance of the torch, thereby decreasing the viscosity of the dopant vapor and increasing its transport rate. This is found to reduce internal tube pressure and eliminate bubble formation in the collapsed preform.

Optical fiber manufacture

A VCSEL comprises separate current and optical guides that provide unique forms of drive current and transverse mode confinement, respectively. In one embodiment, the optical guide comprises an intracavity high refractive index mesa disposed transverse to the cavity resonator axis and a multi-layered dielectric (i.e., non-epitaxial) mirror overlaying the mesa. In another embodiment, the current guide comprises an annular first electrode which laterally surrounds the mesa but has an inside diameter which is greater than that of an ion-implantation-defined current aperture. The current guide causes current to flow laterally from the first electrode along a first path segment which is essentially perpendicular to the resonator axis, then vertically from the first segment along a second path segment essentially parallel to that axis, and finally through the current aperture and the active region to a second electrode. The dielectric mirror is deposited only after the formation of the guides in order to facilitate their fabrication.

Vertical cavity surface-emitting laser with optical guide and current aperture

The invention is an apparatus and method for cleaving a semiconductor bar and coating the cleaved facets within a vacuum environment. The apparatus is a fixture having at least one rotator for cleaving one or more semiconductor samples into semiconductor bars and positioning the semiconductor bars for immediate coating of their cleaved facets. The fixture is operably positioned within a processing chamber and exposed to a conventional coating medium before, during or immediately after cleaving the semiconductor sample. The fixture cleaves the semiconductor samples in a manner that reduces semiconductor sample waste and also allows the processing environment requirements to be reduced compared to other cleaving and coating techniques. A single actuation feed-through mechanism actuates the fixture from outside of the processing chamber.

Fixture and method for laser fabrication by in-situ cleaving of

A process is described of producing devices, such as vertical cavity surface emitting lasers or resonant cavity light emitting devices, with an insulating region between an active region and top electrode, the insulating region having a centrally located window permitting passage of the electric current from the top electrode to the bottom electrode centrally of the active region. The insulating region is formed by ion implantation. The window is defined by a photoresist mask formed by angle etching a photoresist masking layer by RIE, so as to form the mask with parallel side walls inclined at an angle to the normal to the masked surface. The ion implantation is conducted at the same angle and parallel to the side walls of the of the mask. This permits fabrication of devices individually or in arrays. An exemplary independently addressable top emitting 8.times.18 VCSEL array (VCSELA) with GaAs multi-quantum well gain region was fabricated with excellent properties using the angle etched masks. The typical threshold current and voltage of the exemplary devices in this array are approximately 4 mA and 2.65 V respectively. The L-I-V characteristics of the devices do not change by current annealing. Also, a comparison between devices produced by using the novel angled implantation mask and devices produced by using conventional lithography implantation mask indicates the importance of the implantation mask preparation on the final VCSEL operating characteristics.

Fabrication of electronic devices with an internal window

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Plainfield, NJ, United States of America

James Dennis Wynn