Point-wise phase matching for nonlinear frequency generation in dielectric resonators
AssigneeCalifornia Institute of Technology
InventorsNan Yu, Dmitry V. Strekalov, Guoping Lin
Life of this patent
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Abstract
An optical resonator fabricated from a uniaxial birefringent crystal, such as beta barium borate. The crystal is cut with the optical axis not perpendicular to a face of the cut crystal. In some cases the optical axis lies in the plane of the cut crystal face. An incident (input) electromagnetic signal (which can range from the infrared through the visible to the ultraviolet) is applied to the resonator. An output signal is recovered which has a frequency that is an integer multiple of the frequency of the input signal. In some cases a prism is used to evanescently couple the input and the output signals to the resonator.
Claims20
An optical resonator, comprising:
- a birefringent crystal having an optical axis, said birefringent crystal cut so that said optical axis is disposed at an angle different from 0 degrees relative to a direction perpendicular to a cut face of said birefringent crystal, said birefringent crystal configured to operate in a whispering gallery mode of optical propagation, said birefringent crystal configured to receive an input electromagnetic signal having a first frequency f1 and configured to provide in response to said input electromagnetic signal an output electromagnetic signal having a second frequency f2, said first frequency and said second frequency being related according to the relation
- f2=N×f1
- where N is an integer greater than 1.
A method of generating a harmonic of an electromagnetic signal, comprising the steps of:
- providing a birefringent crystal having an optical axis, said birefringent crystal cut so that said optical axis is disposed at an angle different from 0 degrees relative to a direction perpendicular to a cut face of said birefringent crystal;
- applying an input electromagnetic signal having a first frequency f1 to said birefringent crystal;
- operating said birefringent crystal in a whispering gallery mode of optical propagation;
- and
- recovering from said birefringent crystal an output electromagnetic signal having a second frequency f2, said first frequency and said second frequency being related according to the relation
- f2=N×f1
- where N is an integer greater than 1.
Dependencies are inferred from the claim text.