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US3675150A Expired / Lapsed US ⏱️ 0.0 years remaining

Internal modulation of injection lasers using acoustic waves

Assignee: International Business Machines Corp
•
Filing: 1970-06-30
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Granted: 1972-07-04
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Expires: 1990-06-30
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Abstract

Abstract An injection laser whose light output is spatially modulated by internal effects in the active region of the laser. An acoustic wave is launched into the laser and is existent only in a small area including the active region of the laser. In low acoustic frequency operation, the acoustic wave is steered over an angle theta to cause the laser light output to be steered through this angle. In high frequency operation, the frequency of the acoustic wave can be changed to steer the light output, or the acoustic wave can be steered to cause light deflection, as in the low frequency case. The acoustic wave causes phase modulation and loss modulation which results in scanning of the light output. The acoustic wave can be a surface acoustic wave, a Love wave, or a Stonley wave.

Inventors

  • 👤 Erik P Harris
  • 👤 Eric G Lean
  • 👤 Carl G Powell

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-25 16:26
CPC Classifications
H; H01; H01S; H01S5/00; H01S5/06; H01S5/0607; H01S3/00; H01S3/10; H01S3/106; H01S3/1068

Claims Analysis

Total Claims: 19
Claim 1
Independent Claim 166 words
An injection laser providing a spatially varying light output, comprising: a medium of emitting stimulated light when biased with a threshold current, said medium being characterized by a p-n junction plane therein; an angularly degenerate optical cavity capable of sustaining laser oscillations in a plurality of angularly related directions in which said medium is located, said cavity providing optical feedback of said stimulated light; bias means for providing said threshold current to said medium for causing said stimulated light output; means for generating acoustic waves having wavefronts substantially normal to said junction plane and being localized in the vicinity of said junction plane, said acoustic waves producing localized gradients in the index of refraction of said medium, said gradients being normal to said junction plane; means for steering said acoustic waves in a plurality of propagation directions through said medium so that when the acoustic waves are steered in a given direction, the laser oscillations are confined to a direction substantially perpendicular to said given direction.
Claim 2
Dependent Claim 166 words
An injection laser providing a spatially varying light output, comprising: a medium of emitting stimulated light when biased with a threshold current, said medium being characterized by a p-n junction plane therein; an angularly degenerate optical cavity capable of sustaining laser oscillations in a plurality of angularly related directions in which said medium is located, said cavity providing optical feedback of said stimulated light; bias means for providing said threshold current to said medium for causing said stimulated light output; means for generating acoustic waves having wavefronts substantially normal to said junction plane and being localized in the vicinity of said junction plane, said acoustic waves producing localized gradients in the index of refraction of said medium, said gradients being normal to said junction plane; means for steering said acoustic waves in a plurality of propagation directions through said medium so that when the acoustic waves are steered in a given direction, the laser oscillations are confined to a direction substantially perpendicular to said given direction.
Claim 3
Dependent Claim 12 words
The laser of claim 1, wherein said acoustic waves are standing waves.
Claim 4
Dependent Claim 13 words
The laser of claim 1, wherein said acoustic waves are Rayleigh surface waves.
Claim 5
Dependent Claim 25 words
The laser of claim 1, further including a thin film located on said medium, said acoustic waves being Love waves travelling in sAid thin film.
Claim 6
Dependent Claim 31 words
The laser of claim 1, further including a thin film located on said medium, said acoustic waves being Stonley waves travelling along the interface between said thin film and said medium.
Claim 7
Dependent Claim 34 words
The laser of claim 1, where said means for steering includes transducers located on said medium for delivering said acoustic waves to said medium and means for providing variable phase inputs to said transducers.
Claim 8
Dependent Claim 15 words
The laser of claim 1, wherein said bias means includes electrodes located on said medium.
Claim 9
Dependent Claim 37 words
The laser of claim 7, where said acoustic waves are Love waves which travel in one of said electrodes, the velocity of said Love waves in said one electrode being less than their velocity in said medium.
Claim 10
Dependent Claim 23 words
The laser of claim 7, where said acoustic waves are Stonley waves travelling along the interface between said bias electrode and said medium.
Claim 11
Dependent Claim 164 words
An injection laser providing a spatially varying light output, comprising: a medium capable of emitting stimulated light when biased with a threshold current, said medium being characterized by a p-n junction plane therein; optical cavity means in which said medium is located, said cavity means providing optical feedback of said stimulated light in the form of a plurality of parallel light filaments; bias means for providing said threshold current to said medium for causing said stimulated light output; means for generating acoustic waves having wavefronts substantially normal to said junction plane and being localized in the vicinity of said p-n junction plane, said acoustic waves producing localized gradients in the index of refraction of said medium in a direction normal to said junction plane; means for changing the frequency of said acoustic waves to cause spatial scanning of said light output to vary the spatial periodicity and phase velocity of the light filaments which oscillate within the junction causing the output to be scanned.
Claim 12
Dependent Claim 164 words
An injection laser providing a spatially varying light output, comprising: a medium capable of emitting stimulated light when biased with a threshold current, said medium being characterized by a p-n junction plane therein; optical cavity means in which said medium is located, said cavity means providing optical feedback of said stimulated light in the form of a plurality of parallel light filaments; bias means for providing said threshold current to said medium for causing said stimulated light output; means for generating acoustic waves having wavefronts substantially normal to said junction plane and being localized in the vicinity of said p-n junction plane, said acoustic waves producing localized gradients in the index of refraction of said medium in a direction normal to said junction plane; means for changing the frequency of said acoustic waves to cause spatial scanning of said light output to vary the spatial periodicity and phase velocity of the light filaments which oscillate within the junction causing the output to be scanned.
Claim 13
Dependent Claim 13 words
The laser of claim 10, wherein said acoustic waves are surface acoustic waves.
Claim 14
Dependent Claim 19 words
The laser of claim 10, having a thin film located on said medium in which acoustic Love waves travel.
Claim 15
Dependent Claim 31 words
The laser of claim 10, having a thin film located on said medium, where said acoustic waves are Stonley waves travelling along the interface between said thin film and said medium.
Claim 16
Dependent Claim 15 words
The laser of claim 10, where said bias means includes electrodesl connected to said medium.
Claim 17
Dependent Claim 37 words
The laser of claim 14, wherein said acoustic waves are Love waves which travel in one of said electrodes, the velocity of said love waves in said one electrode being less than their velocity in said medium.
Claim 18
Dependent Claim 24 words
The laser of claim 14, wherein said acoustic waves are Stonley waves travelling along the interface between one of said electrodes and said medium.
Claim 19
Dependent Claim 12 words
The laser of claim 10, wherein said acoustic waves are standing waves.

References Cited (Backward Citations)

US3245002A Cited
US3530400A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1975-07-04 1976-01-03 1976-07-04 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1979-07-04 1980-01-03 1980-07-04 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1983-07-04 1984-01-03 1984-07-04 $7700.00 Window Closed / Lapsed

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