Wavelength conversion element
AssigneeRicoh Company, Ltd.
InventorsHiroaki Fukuda, Hiroyoshi Funato, Shigeyoshi Misawa
Life of this patent
Estimating the term…
Abstract
A wavelength conversion element includes a substrate made of LiTaO.sub.3 of non-linear medium, a three-dimensional waveguide formed in the substrate and a second harmonic generation portion for defining a change in refractive index in the waveguide with a period .LAMBDA. and generating a second harmonic of a fundamental wave introduced into the wave guide, where .LAMBDA.=2m.pi./{.beta.(2.omega.)-2.beta.(.omega.)}, m is a natural number, .omega. is a frequency of fundamental harmonic, .beta.(.omega.) is a propagation constant of the fundamental wave, and .beta.(2.omega.) is a propagation constant of second harmonic.
Claims17
A wavelength conversion element comprising:
- a substrate made of LiTaO.sub.3, LiNbO.sub.3 or LiNbO.sub.3 doped with MgO of non-linear optical medium;
- a plurality of three-dimensional waveguides formed in the substrate and crossed on the substrate;
- a potential difference application means formed on an intersection to apply a potential difference for change of optical path of a fundamental wave guided through a waveguide;
- and
- a second harmonic generation means formed on at least one of the plurality of waveguides for defining a change in refractive index in a waveguide with a period .LAMBDA. and generating a second harmonic of the fundamental wave introduced into the waveguide, where .LAMBDA.=2m.pi./{.beta.(2.omega.)-2.beta.(.omega.)}, where m is a natural number, .omega. is a frequency of the fundamental wave, .beta.(.omega.) is a propagation constant of the fundamental wave, and .beta.(2.omega.) is a propagation constant of the second harmonic.
A wavelength conversion element comprising:
- a substrate of non-linear optical medium;
- a plurality of three-dimensional waveguides formed in the substrate and crossed on the substrate;
- a potential difference application means formed on an intersection to apply a potential difference for change of optical path of a fundamental wave guided through a waveguide;
- and
- a shorter wavelength harmonic generation means formed on at least one of the plurality of waveguides for generating a shorter wavelength harmonic from the fundamental wave introduced into the waveguide.
A wavelength conversion element comprising:
- a substrate made of LiTaO.sub.3, LiNbO.sub.3 or LiNbO.sub.3 doped with MgO of non-linear medium;
- a three-dimensional waveguide formed in the substrate;
- and
- a second harmonic generation means for defining a change in refractive index in the waveguide with a period .LAMBDA. and generating a second harmonic of a fundamental wave introduced into the waveguide, where .LAMBDA.=2m.pi./{.beta.(2.omega.)-2.beta.(.omega.)}, where m is a natural number, .omega. is a frequency of the fundamental wave, .beta.(.omega.) is a propagation constant of the fundamental wave, and .beta.(2.omega.) is a propagation constant of the second harmonic,
- wherein a y-directional polarization with a direction of an electric field parallel to a y axis is used as the fundamental wave and a polarization with a direction of an electric field parallel to an x axis is used as the second harmonic in a case where a .+-.c plate is used as the substrate, a direction of light propagation is taken as a z axis and a .+-.c axis of the substrate is taken as the x axis perpendicular to the z axis.
Dependencies are inferred from the claim text.