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US 12,723,863 B2Granted
Second harmonic generation (SHG) measurement device and measurement method using the same
AssigneeSamsung Electronics Co., Ltd.
InventorsHidaka Yasuhiro, Ingi Kim
Life of this patent
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Abstract
A measurement device includes a light source configured to emit a fundamental wave that is a femtosecond pulsed laser beam, a second harmonic generator configured to convert a portion of the fundamental wave into a first-second harmonic, a birefringent crystal configured to split an angle for the first-second harmonic, a wavelength selection element configured to block the fundamental wave and transmit therethrough the first-second harmonic and a second-second harmonic, a polarizer configured to polarize the first-second harmonic and the second-second harmonic to approximately same polarizations, and an image detector.
Claims20
A measurement device, comprising:
- a light source configured to emit a fundamental wave that is a femtosecond pulsed laser beam;
- a second harmonic generator configured to convert a portion of the fundamental wave into a first-second harmonic;
- a birefringent crystal configured to split an angle for the first-second harmonic;
- a wavelength selection element configured to block the fundamental wave and transmit therethrough the first-second harmonic and a second-second harmonic;
- a polarizer configured to polarize the first-second harmonic and the second-second harmonic to have approximately a same polarization;
- an image detector configured to convert the first-second harmonic and the second-second harmonic, which are incident at different angles from each other, into an electrical signal;
- and
- a processing device configured to obtain a strength of the second-second harmonic from an amplitude of an interference pattern appearing on the image detector,
- wherein a wavelength of the first-second harmonic is approximately half a wavelength of the fundamental wave, and the second-second harmonic is generated by casting the fundamental wave onto a surface of an object to be measured.
6 more elements
A measurement device, comprising:
- a second harmonic generator comprising a nonlinear optical crystal configured to convert, into a first-second harmonic, a portion of a fundamental wave emitted from a light source;
- a condensing lens configured to concentrate the fundamental wave onto the second harmonic generator;
- a birefringent crystal configured to split an angle for the first-second harmonic;
- a collimator lens arranged between the second harmonic generator and the birefringent crystal, and configured to refract the fundamental wave and the first-second harmonic to form parallel light;
- a wavelength selection element configured to block the fundamental wave and transmit therethrough the first-second harmonic and a second-second harmonic;
- a polarizer arranged between a plurality of relay lens and configured to polarize the first-second harmonic and the second-second harmonic to approximately same polarizations;
- an image detector configured to convert the first-second harmonic and the second-second harmonic, which are incident at different angles from each other, into an electrical signal;
- a processing device configured to obtain a strength of the second-second harmonic from an amplitude of an interference pattern appearing on the image detector;
- a wavelength plate configured to transform, into circular polarization, the first-second harmonic of which the angle is split by the birefringent crystal;
- and
- a beam splitter configured to split, into two polarization components, the first-second harmonic having passed through the wavelength selection element and the second-second harmonic having passed through the wavelength selection element.
8 more elements
A measurement device, comprising:
- a second harmonic generator comprising a nonlinear optical crystal configured to convert, into a first-second harmonic, a portion of a fundamental wave emitted from a light source;
- a condensing lens configured to concentrate the fundamental wave onto the second harmonic generator;
- a birefringent crystal configured to split an angle for the first-second harmonic;
- a collimator lens arranged between the second harmonic generator and the birefringent crystal and configured to refract the fundamental wave and the first-second harmonic to form parallel light;
- a wavelength selection element configured to block the fundamental wave and transmit therethrough the first-second harmonic and a second-second harmonic;
- a polarizer arranged between a plurality of relay lens and configured to polarize the first-second harmonic and the second-second harmonic to approximately same polarizations;
- an image detector configured to convert the first-second harmonic and the second-second harmonic, which are incident at different angles from each other, into an electrical signal;
- a processing device configured to obtain a strength of the second-second harmonic from an amplitude of an interference pattern appearing on the image detector;
- a wavelength plate configured to transform, into circular polarization, the first-second harmonic of which the angle is split by the birefringent crystal;
- and
- a beam splitter configured to split, into two polarization components, the first-second harmonic having passed through the wavelength selection element and the second-second harmonic having passed through the wavelength selection element,
- wherein the image detector comprises:
- a first image detector configured to convert, into an electrical signal, one of the two polarization components of the second-second harmonic split by the beam splitter;
- and
- a second image detector configured to convert the other of the two polarization components into an electrical signal, and
- wherein the wavelength selection element comprises:
- a prism configured to change a traveling direction of light for each wavelength;
- a refractive grating configured to change a traveling direction of light for each wavelength;
- and
- a relay lens iris configured to transmit therethrough the first-second harmonic and the second-second harmonic.
17 more elements
Dependencies are inferred from the claim text.