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Browse Prior Art Database

Laser Diode with Integrated Electronic Beam Steering

IP.com Disclosure Number: IPCOM000105283D
Original Publication Date: 1993-Jul-01
Included in the Prior Art Database: 2005-Mar-19
Document File: 2 page(s) / 51K

Publishing Venue

IBM

Related People

Gfeller, F: AUTHOR

Abstract

Disclosed is a diode laser structure 10 allowing a lateral displacement of the exit beam axis by means of differential injection of charge carriers into the active layer. Such devices may be useful for applications to optical storage where the focused light spot is electronically scanned to follow the optical disc track at much higher speed than achievable with mechanical movement of the objective lens.

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Laser Diode with Integrated Electronic Beam Steering

      Disclosed is a diode laser structure 10 allowing a lateral
displacement of the exit beam axis by means of differential injection
of charge carriers into the active layer.  Such devices may be useful
for applications to optical storage where the focused light spot is
electronically scanned to follow the optical disc track at much
higher speed than achievable with mechanical movement of the
objective lens.

      The device structure is shown in the Figure using a SQW-GRINSCH
laser embodiment with flared ridge 11, drive current electrode 12,
beam steering electrodes 13a,b and 14a,b, and etched grooves 15
providing electrical isolation of the electrodes.

      Beam deflection is achieved in two stages:  In the first stage,
the active layer below electrode 13b is pumped to optical
transparency, while the refractive index of the active layer below
electrode 13a is lowered by injecting a current vbar sub 1 .gt vbar
sub 2.  The resulting index gradient across the electrode gap causes
a deflection of the laterally unguided beam depending on the current
ratio vbar sub 1 / vbar sub 2.  In the second deflector stage the
process is reversed resulting in a lateral beam displacement &Delta.x
of a few micrometers.  The two-stage deflection provides approximate
cancellation of any undesired angular beam deflection at the exit
facet and further avoids excessive mirror coupling losses.
Experimental results have show...