Second harmonic generation method and apparatus
AssigneeSamsung Electronics Co., Ltd.
InventorsHang-woo Lee, Sang-hak Lee, Joseph Kilwhoan Chee, Young-mo Hwang, Yurij V. Tsvetkov, Alexander V. Semenenko, Ivan I. Kuratev
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Abstract
A second harmonic generation apparatus provides a polarization element transmitting only light polarized in an extra-ordinary axis direction on the proceeding path of a second harmonic emitted from a resonator. The light polarized in the extra-ordinary axis direction is transmitted to a beam splitter, and a part of the polarized light is fed back to a feedback circuit, so that the temperature of a non-linear birefringent crystalline element inside resonator can be stably controlled and the output second harmonic can be stably produced.
Claims6
A method for generating a second harmonic, which comprises the steps of:
- generating a fundamental wave by exciting a birefringent crystalline gain medium with a pumping laser;
- generating a second harmonic by exciting a non-linear birefringent crystalline element with said fundamental wave;
- polarizing said second harmonic and transmitting a specific polarized light of said second harmonic;
- separating a part of said polarized light and feeding said part back to a control circuit;
- converting the feedback light into an electrical signal;
- and
- controlling the temperature of said non-linear birefringent crystalline element with said electrical signal.
A second harmonic generation apparatus comprising:
- a resonator provided with an input mirror and an output mirror;
- a non-linear birefringent crystalline element and a gain medium provided on an optical axis placed in said resonator;
- a temperature control device controlling the temperature of said non-linear birefringent crystalline element;
- a beam splitter provided on the path of the second harmonic transmitted from said output mirror, and reflecting part of the second harmonic to an other path;
- a polarization element provided in between the output mirror and said beam splitter, and transmitting the light polarized in a specific direction;
- an optical detector provided on a path of said second harmonic reflected by said beam splitter;
- and
- a control circuit controlling said temperature control device with the signal emitted from said optical detector.
Dependencies are inferred from the claim text.