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US5233620A Expired / Lapsed US ⏱️ 0.0 years remaining

Second-harmonic generating apparatus

Assignee: Oki Electric Industry Co Ltd
•
Filing: 1991-08-27
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Granted: 1993-08-03
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Expires: 2011-08-27
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Abstract

Abstract A second-harmonic generating device includes a laser diode for providing light of a fundamental wave, having end-facets at least one being an antireflection coated end-facet. An optical reflector forms an external resonator with one of the end-facets of the laser diode whereby a portion of the light from the laser diode is returned by the reflector to the laser diode. A second-harmonic generation element is disposed between the laser diode and the optical reflector, for producing a second-harmonic of the fundamental wave while the fundamental wave propagates in the second-harmonic generation element. In this way, the optical reflector determines the wavelength of the light of the fundamental wave so that the laser diode produces light with a wavelength satisfying a phase matching condition of the second-harmonic generation element.

Inventors

  • 👤 Keisuke Shinozaki
  • 👤 Saeko Oshiba
  • 👤 Takeshi Kamijoh

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-08 02:49
CPC Classifications
H; H01; H01S; H01S3/00; H01S3/10; H01S3/106; H01S3/108; H01S3/109; H01S5/00; H01S5/10; H01S5/14; H01S5/141

Claims Analysis

Total Claims: 15
Claim 1
Independent Claim 159 words
A second-harmonic generating apparatus comprising: a laser diode for providing light of a fundamental wave, having a high reflection coated end-facet and an antireflection coated end-facet; an optical reflector for forming an external resonator with said high reflection coated end-facet of said laser diode whereby a portion of the light from said laser diode is returned by said optical reflector to said laser diode; and second-harmonic generation means, disposed between said antireflection coated end-facet of said laser diode and said optical reflector, for producing a second-harmonic of said fundamental wave while said fundamental wave propagates in said second-harmonic generation means; wherein said optical reflector determines the wavelength of said light of said fundamental wave so that said laser diode produces light with a wavelength satisfying a phase matching condition of said second-harmonic generation means; said apparatus further comprising an optical filter for receiving a portion of the light from said optical reflector and filtering out said fundamental wave therefrom.
Claim 2
Dependent Claim 159 words
A second-harmonic generating apparatus comprising: a laser diode for providing light of a fundamental wave, having a high reflection coated end-facet and an antireflection coated end-facet; an optical reflector for forming an external resonator with said high reflection coated end-facet of said laser diode whereby a portion of the light from said laser diode is returned by said optical reflector to said laser diode; and second-harmonic generation means, disposed between said antireflection coated end-facet of said laser diode and said optical reflector, for producing a second-harmonic of said fundamental wave while said fundamental wave propagates in said second-harmonic generation means; wherein said optical reflector determines the wavelength of said light of said fundamental wave so that said laser diode produces light with a wavelength satisfying a phase matching condition of said second-harmonic generation means; said apparatus further comprising an optical filter for receiving a portion of the light from said optical reflector and filtering out said fundamental wave therefrom.
Claim 3
Dependent Claim 16 words
A second-harmonic generating apparatus according to claim 1, wherein said optical reflector comprises a diffraction grating.
Claim 4
Dependent Claim 18 words
A second-harmonic generating apparatus according to claim 1, wherein said optical reflector comprises a prism and a mirror.
Claim 5
Dependent Claim 17 words
A second-harmonic generating apparatus according to claim 1, wherein said second-harmonic generation means is a waveguide-type element.
Claim 6
Dependent Claim 18 words
A second-harmonic generating apparatus according to claim 1, wherein said second-harmonic generation means operates based on quasi-phase matching.
Claim 7
Dependent Claim 27 words
A second-harmonic generating apparatus according to claim 1, further comprising a half-wave plate disposed between said antireflective end-facet of said laser diode and said second-harmonic generation means.
Claim 8
Dependent Claim 151 words
A second-harmonic generating apparatus comprising: a laser diode for providing light of a fundamental wave, having a high reflection coated end-facet and an antireflection coated end-facet; an optical reflector for forming an external resonator with said high reflection coated end-facet of said laser diode whereby a portion of the light from said laser diode is returned by said optical reflector to said laser diode; and second-harmonic generation means, disposed between said antireflection coated end-facet of said laser diode and said optical reflector, for producing a second-harmonic of said fundamental wave while said fundamental wave propagates in said second-harmonic generation means; wherein said optical reflector determines the wavelength of said light of said fundamental wave so that said laser diode produces light with a wavelength satisfying a phase matching condition of said second-harmonic generation means; said apparatus further comprising a collimating lens disposed between said optical reflector and said second-harmonic generation means.
Claim 9
Dependent Claim 151 words
A second-harmonic generating apparatus comprising: a laser diode for providing light of a fundamental wave, having a high reflection coated end-facet and an antireflection coated end-facet; an optical reflector for forming an external resonator with said high reflection coated end-facet of said laser diode whereby a portion of the light from said laser diode is returned by said optical reflector to said laser diode; and second-harmonic generation means, disposed between said antireflection coated end-facet of said laser diode and said optical reflector, for producing a second-harmonic of said fundamental wave while said fundamental wave propagates in said second-harmonic generation means; wherein said optical reflector determines the wavelength of said light of said fundamental wave so that said laser diode produces light with a wavelength satisfying a phase matching condition of said second-harmonic generation means; said apparatus further comprising a collimating lens disposed between said optical reflector and said second-harmonic generation means.
Claim 10
Dependent Claim 16 words
A second-harmonic generating apparatus according to claim 7, wherein said optical reflector comprises a diffraction grating.
Claim 11
Dependent Claim 18 words
A second-harmonic generating apparatus according to claim 7, wherein said optical reflector comprises a prism and a mirror.
Claim 12
Dependent Claim 177 words
A second-harmonic generating apparatus comprising: a laser diode for providing light of a fundamental wave, having a high reflection coated end-facet and an antireflection coated end-facet; an optical reflector for forming an external resonator with said high reflection coated end-facet of said laser diode whereby a portion of the light from said laser diode is returned by said optical reflector to said laser diode; and second-harmonic generation means, disposed between said antireflection coated end-facet of said laser diode and said optical reflector, for producing a second-harmonic of said fundamental wave while said fundamental wave propagates in said second-harmonic generation means; wherein said optical reflector determines the wavelength of said light of said fundamental wave so that said laser diode produces light with a wavelength satisfying a phase matching condition of said second-harmonic generation means; wherein said second-harmonic generation means comprises a substrate having an optical waveguide formed in a surface thereof and extending along an axis thereof, and having a plurality of spaced apart domain-reversing regions formed in said surface as stripes extending orthogonal to said axis.
Claim 13
Dependent Claim 177 words
A second-harmonic generating apparatus comprising: a laser diode for providing light of a fundamental wave, having a high reflection coated end-facet and an antireflection coated end-facet; an optical reflector for forming an external resonator with said high reflection coated end-facet of said laser diode whereby a portion of the light from said laser diode is returned by said optical reflector to said laser diode; and second-harmonic generation means, disposed between said antireflection coated end-facet of said laser diode and said optical reflector, for producing a second-harmonic of said fundamental wave while said fundamental wave propagates in said second-harmonic generation means; wherein said optical reflector determines the wavelength of said light of said fundamental wave so that said laser diode produces light with a wavelength satisfying a phase matching condition of said second-harmonic generation means; wherein said second-harmonic generation means comprises a substrate having an optical waveguide formed in a surface thereof and extending along an axis thereof, and having a plurality of spaced apart domain-reversing regions formed in said surface as stripes extending orthogonal to said axis.
Claim 14
Dependent Claim 40 words
A second-harmonic generating apparatus according to claim 10, wherein said substrate comprises LiNbO 3 , wherein said domain-reversing regions comprise titanium diffused in said surface of said substrate, and wherein said optical waveguide is formed by a proton exchanging process.
Claim 15
Dependent Claim 78 words
A second-harmonic generating apparatus according to claim 10, wherein said domain-reversing regions are spaced apart along said axis by a coherence length l c , the domain-reversing regions having a width along said axis of said coherence length l c , the domain-reversing regions being thereby formed with a spatial period of 2l c , whereby the power of the second-harmonic of the fundamental wave is approximately proportional to the square of the length of the optical waveguide.

References Cited (Backward Citations)

JPS6394686A Cited
US4910738A Cited
US4959665A Cited
US5036220A Cited
US5036220B1 Cited
US5082340A Cited
DE9102316U1 Cited
US5068546A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1996-08-02 1997-02-01 1997-08-03 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 2000-08-02 2001-02-01 2001-08-03 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 2004-08-02 2005-02-01 2005-08-03 $7700.00 Window Closed / Lapsed

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