Browse Prior Art Database

SOLID STATE HETEROSTRUCTURE LASER DEVICES FOR OPTICAL RECORDING

IP.com Disclosure Number: IPCOM000025915D
Original Publication Date: 1988-Dec-31
Included in the Prior Art Database: 2004-Apr-04
Document File: 2 page(s) / 159K

Publishing Venue

Xerox Disclosure Journal

Abstract

There are applications for solid state lasers in optical disk memory tracking that require periodical varying of the position of a laser beam for purposes of tracking, which is referred to as beam dithering. A simple way to accomplish this goal is to employ multi-electrode stripe geometry on the laser and modulate the current between two or among several of electrodes at a desired modulation rate. This approach would remove the need for a electromechanical or piezo-electric dither mirror in an optical memory system having a wobble or dither tracking optical disk drive, which type of mirror has low reliability .

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XEROX DISCLOSURE JOURNAL

SOLID STATE HETEROSTRUCTURE Proposed Classification LASER DEVICES FOR OPTICAL
RECORDING
Int. C1. HOls 3/19 William Streifer
Donald
R. Scifres
Robert
D. Burnham

U.S. C1.372/46

- - FIG. IA

30

37 -7+

FIG. 2

Volume 13 Number 6 NovembedDecember 1988 339

[This page contains 1 picture or other non-text object]

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SOLID STATE HETEROSTRUCTURE LASER DEVICES FOR 0 PTICAL RECORDING (Cont'd)

There are applications for solid state lasers in optical disk memory tracking that require periodical varying of the position of a laser beam for purposes of tracking, which is referred to as beam dithering. A simple way to accomplish this goal is to employ multi-electrode stripe geometry on the laser and modulate the current between two or among several of electrodes at a desired modulation rate. This approach would remove the need for a electromechanical or piezo-electric dither mirror in an optical memory system having a wobble or dither tracking optical disk drive, which type of mirror has low reliability .

Fig. I illustrates a typical heterostructure laser 10 with output beam 12 with two contacts 14 and 16 separated by an etched groove 15. Current pumping is accomplished through regions 18 and 20, which are elongated openings in insulating Si3N4 layer 22. This structure is similar to the laser structure shown in USP 4,217,561. By applying a high frequency modulation between stripe contacts 14 and 16 in addition to the normal pumping current, via the circuit shown in Fig. IA, output beam 12 will be shifted laterally back and forth in a dither motion, as indicated a...