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EP0473441A2 Expired / Lapsed EP ⏱️ 0.0 years remaining

Harmonic generating apparatus

Assignee: Oki Electric Industry Co Ltd
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Filing: 1991-08-29
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Granted: —
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Expires: 2011-08-29
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Abstract

Abstract A second-harmonic generating apparatus comprises a laser diode (20), a tunable reflector (40) and a SHG element (32). The laser diode provides light at a fundamental wavelength. The relector forms a resonator with one of end-facet (24) of the laser diode so that the laser diode oscillates. The SHG element (32) is disposed between the laser diode and the reflector, and produces a second-harmonic whilst the fundamental wave propagates in it. The tunable reflector (40) in one embodiment comprises a grating which selects a wavelength for the fundamental wave that causes the laser diode to oscillate with a wavelength satisfying a phase matching condition of the SHG element, so as to maximise production of the second harmonic. As an alternative to the grating (40) a prism and a reflector can be used for wavelength selection.

Inventors

  • 👤 Keisuke C/O Oki Electric Ind. Co. Ltd. Shinozaki
  • 👤 Saeko C/O Oki Electric Ind. Co. Ltd. Oshiba
  • 👤 Takeshi C/O Oki Electric Ind. Co. Ltd. Kamijoh

Bibliographic Details

Application Number —
Jurisdiction EP
Data Source google_patents
Last Synchronized 2026-11-08 02:39
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: 14
Claim 1
Independent Claim 90 words
Harmonic generating apparatus comprising laser means (20, 50) for producing laser radiation at a fundamental frequency, and a harmonic generating element (32) for generating a predetermined harmonic of said fundamental frequency, chac- terised by wavelength tunable means (40, 80) for tuning the frequency of the fundamental fed back into the laser means to achieve laser oscillation thereof after passage of said fundamental through the harmonic generating element (32), whereby to permit tuning of the fundamental to a frequency which maximises production of said predetermined harmonic by said harmonic generating element.
Claim 2
Dependent Claim 90 words
Harmonic generating apparatus comprising laser means (20, 50) for producing laser radiation at a fundamental frequency, and a harmonic generating element (32) for generating a predetermined harmonic of said fundamental frequency, chac- terised by wavelength tunable means (40, 80) for tuning the frequency of the fundamental fed back into the laser means to achieve laser oscillation thereof after passage of said fundamental through the harmonic generating element (32), whereby to permit tuning of the fundamental to a frequency which maximises production of said predetermined harmonic by said harmonic generating element.
Claim 3
Dependent Claim 102 words
A second-harmonic generating apparatus comprising: a laser diode for providing a fundamental wave, having at least one antireflection coated end-faset ; an optical reflector for forming a resonator with one of end-faset of said laser diode so that said laser diode oscillates ; and an SHG element disposed between said laser diode and said optical reflector for producing a second-harmonic of said fundamental wave while said fundamental wave propagates in said SHG element; wherein said optical reflector selects a wavelength of said fundamental wave so that said laser diode oscillates with a wavelength satisfying a phase matching condition of said SHG element.
Claim 4
Dependent Claim 102 words
A second-harmonic generating apparatus comprising: a laser diode for providing a fundamental wave, having at least one antireflection coated end-faset ; an optical reflector for forming a resonator with one of end-faset of said laser diode so that said laser diode oscillates ; and an SHG element disposed between said laser diode and said optical reflector for producing a second-harmonic of said fundamental wave while said fundamental wave propagates in said SHG element; wherein said optical reflector selects a wavelength of said fundamental wave so that said laser diode oscillates with a wavelength satisfying a phase matching condition of said SHG element.
Claim 5
Dependent Claim 113 words
A second-harmonic ganerating apparatus comprising ; a laser diode for providing a fundamental wave, having a high reflection coated end-faset and an antireflection coated end-faset ; an optical reflector for composing a resonator with said high reflection coated end-faset of said laser diode so that said laser diode oscillates ; and an SHG element disposed between said antireflection coated end-faset of laser diode and said optical reflector for producing a second-harmonic of said fundamental wave while fundamental wave propagates in said SHG element ; wherein said optical reflector selects a wavelength of said fundamental wave so that said laser diode oscillates with a wavelength satisfying a phase matching condition of said SHG element.
Claim 6
Dependent Claim 113 words
A second-harmonic ganerating apparatus comprising ; a laser diode for providing a fundamental wave, having a high reflection coated end-faset and an antireflection coated end-faset ; an optical reflector for composing a resonator with said high reflection coated end-faset of said laser diode so that said laser diode oscillates ; and an SHG element disposed between said antireflection coated end-faset of laser diode and said optical reflector for producing a second-harmonic of said fundamental wave while fundamental wave propagates in said SHG element ; wherein said optical reflector selects a wavelength of said fundamental wave so that said laser diode oscillates with a wavelength satisfying a phase matching condition of said SHG element.
Claim 7
Dependent Claim 16 words
A second-harmonic generating apparatus according to claim 2, wherein said optical reflector comprises a diffraction grating.
Claim 8
Dependent Claim 18 words
A second-harmonic generating apparatus according to claim 2, wherein said optical reflector comprises a prism and a mirror.
Claim 9
Dependent Claim 14 words
A second-harmonic generating apparatus according to claim 2, wherein said SHG element is waveguide-type.
Claim 10
Dependent Claim 17 words
A second-harmonic generating apparatus according to claim 2, wherein said SHG element is based on quasi-phase matching.
Claim 11
Dependent Claim 149 words
A second-harmonic generating apparatus comprising: a laser diode for providing a fundamental wave, having both antireflection coated end-fasets; a first optical fiber disposed adjacent to said laser diode for receiving a light emitted from one of said end-fasets of said laser diode; a second optical fiber disposed adjacent to said laser diode for sending back a light to the opposite end-faset of said laser diode; an optical selector disposed between said first and second optical fibers for selecting a wavelength of a light from said first optical fiber and supplying a light having the selected wavelength to said second optical fiber; and an SHG element disposed between said laser diode and said first optical fiber for producing a second-harmonic of said fundamental wave while said fumdamental wave propagates in said SHG element; wherein said laser diode oscillates with a wavelength satisfing a phase matching condition of said SHG element
Claim 12
Dependent Claim 149 words
A second-harmonic generating apparatus comprising: a laser diode for providing a fundamental wave, having both antireflection coated end-fasets; a first optical fiber disposed adjacent to said laser diode for receiving a light emitted from one of said end-fasets of said laser diode; a second optical fiber disposed adjacent to said laser diode for sending back a light to the opposite end-faset of said laser diode; an optical selector disposed between said first and second optical fibers for selecting a wavelength of a light from said first optical fiber and supplying a light having the selected wavelength to said second optical fiber; and an SHG element disposed between said laser diode and said first optical fiber for producing a second-harmonic of said fundamental wave while said fumdamental wave propagates in said SHG element; wherein said laser diode oscillates with a wavelength satisfing a phase matching condition of said SHG element
Claim 13
Dependent Claim 16 words
A second-harmonic generating apparatus according to claim 8, wherein said optical selector comprises a diffraction grating.
Claim 14
Dependent Claim 18 words
A second-harmonic generating apparatus according to claim 8, wherein said optical selector comprises a prism and a mirror.

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