Abstract: An inspection device includes: a light source for outputting pulsed excitation light with a time width of 10 picoseconds to 10 nanoseconds; a nonlinear optical crystal for generating a terahertz wave by optical wavelength conversion of the excitation light; and a detector for detecting a reflected wave of the terahertz wave reflected by an inspection target.

Abstract: An inspection device includes: a light source for outputting pulsed excitation light with a time width of 10 picoseconds to 10 nanoseconds; a nonlinear optical crystal for generating a terahertz wave by optical wavelength conversion of the pulsed excitation light; a polarization part for reflecting at least a part of a reflected wave of the terahertz wave reflected by an inspection target; and a detector for detecting the reflected wave reflected by the polarization part.

Abstract: A transistor (2) and a matching circuit substrate (3-6) are provided on a base plate (1) and connected to each other. A frame (15) is provided on the base plate (1) and surrounds the transistor (2) and the matching circuit substrate (3-6). The frame (15) has a smaller linear expansion coefficient than that of the base plate (1). A screwing portion (17) is provided in the frame (15). A size of the base plate (1) is smaller than that of the frame (15).

Abstract: A terahertz-wave generation method of generating a terahertz wave in a direction satisfying a non-collinear phase-matching condition by making pump light incident on a nonlinear optical crystal capable of generating a terahertz wave by optical parametric effect, makes the pump light incident on the nonlinear optical crystal so that a peak excited power density is equal to or greater than a predetermined terahertz-wave lasing threshold and equal to or less than a predetermined laser damage threshold, and an average excited power density, is equal to or less than a predetermined photorefractive effect occurrence threshold, the pump light having a pulse width of 10 ps or more, the pulse width of 1 ns or less, and a repetition frequency of 1 kHz or more.

Abstract: A transistor (2) and a matching circuit substrate (3-6) are provided on a base plate (1) and connected to each other. A frame (15) is provided on the base plate (1) and surrounds the transistor (2) and the matching circuit substrate (3-6). The frame (15) has a smaller linear expansion coefficient than that of the base plate (1). A screwing portion (17) is provided in the frame (15). A size of the base plate (1) is smaller than that of the frame (15).

Abstract: In order to accomplish highly-efficient nonlinear optical wavelength conversion for terahertz waves by using a simple configuration, an embodiment of the present invention provides a terahertz wave generating device 100 provided with a pump light source 104 that generates pump light LP of a single wavelength and a nonlinear optical element (periodical polarization inversion element) 102. The nonlinear optical element has a periodic structure in which the polarization or the crystal orientation is periodically inverted with a certain inversion period ?. When the pump light enters the nonlinear optical element, idler light LI and signal light LTHz are generated.

Abstract: A pulsed electromagnetic-wave generator includes an excitation light source, a laser resonator, a pulse generating unit, and a wavelength converting unit. Excitation light from the excitation light source enters the laser resonator. The pulse generating unit is configured to generate a pulsed light group including at least two or more pulses with different frequencies (?) and different oscillation timings (t) in one excitation process of the excitation light source, an oscillation frequency difference (??) between the pulses in the pulsed light group being an integral multiple of a Free Spectral Range (FSR) of the laser resonator. The pulsed light group enters the wavelength converting unit. The wavelength converting unit is configured to generate a pulsed electromagnetic wave in which a wavelength of each pulse in the pulsed light group is converted.

Abstract: A terahertz-wave generation method of generating a terahertz wave in a direction satisfying a non-collinear phase-matching condition by making pump light incident on a nonlinear optical crystal capable of generating a terahertz wave by optical parametric effect, makes the pump light incident on the nonlinear optical crystal so that a peak excited power density is equal to or greater than a predetermined terahertz-wave lasing threshold and equal to or less than a predetermined laser damage threshold, and an average excited power density is equal to or less than a predetermined photorefractive effect occurrence threshold, the pump light having a pulse width of 10 ps or more, the pulse width of 1 ns or less, and a repetition frequency of 1 kHz or more.

Abstract: In order to accomplish highly-efficient nonlinear optical wavelength conversion for terahertz waves by using a simple configuration, an embodiment of the present invention provides a terahertz wave generating device 100 provided with a pump light source 104 that generates pump light LP of a single wavelength and a nonlinear optical element (periodical polarization inversion element) 102. The nonlinear optical element has a periodic structure in which the polarization or the crystal orientation is periodically inverted with a certain inversion period ?. When the pump light enters the nonlinear optical element, idler light LI and signal light LTHz are generated.

Abstract: A pulsed electromagnetic-wave generator includes an excitation light source, a laser resonator, a pulse generating unit, and a wavelength converting unit. Excitation light from the excitation light source enters the laser resonator. The pulse generating unit is configured to generate a pulsed light group including at least two or more pulses with different frequencies (?) and different oscillation timings (t) in one excitation process of the excitation light source, an oscillation frequency difference (??) between the pulses in the pulsed light group being an integral multiple of a Free Spectral Range (FSR) of the laser resonator. The pulsed light group enters the wavelength converting unit. The wavelength converting unit is configured to generate a pulsed electromagnetic wave in which a wavelength of each pulse in the pulsed light group is converted.

Abstract: An optical response measuring device is provided with a light source, first and second wavelength conversion elements and a light intensity sensor array. The light source generates a pair of light beams including light beams of first and second wavelengths, and the first wavelength conversion element generates measurement light. The measurement light is irradiated on an object for measurement and a detection light having first phase and second phase is obtained in response to this irradiation. A reference light that carries the phase of the pair of the pair light beams and the detection light both pass through a second wavelength conversion element to obtain a modulated reference light have first and second intensities. The first and second local intensities are then measured by the light intensity sensor array.

Abstract: An optical response measuring device is provided with a light source, first and second wavelength conversion elements, and a light intensity sensor array. The light source generates a pair of light beams including light beams of first and second wavelengths. The first wavelength conversion element generates measurement light of a wavelength whose phase is maintained with relative to the pair of light beams incident thereon. The measurement light is irradiated to an object for measurement. The detected light is then made incident on the second wavelength conversion element. Reference light carries the phase of the pair of light beams and light for which the phase is to be determined in the detection light, from which the second wavelength conversion element generates modulated reference light. The modulated reference light is modulated to have first and second local intensities, which are then measured by the light intensity sensor array.

Abstract: The present invention includes a slanted periodically poled device 12 including a light input surface 12a and a light output surface 12b parallel to each other and a terahertz wave input surface 12c orthogonal to the light input surface 12a and the light output surface 12b, a pump beam source 14 which emits pump beam 1 perpendicularly to the light input surface 12a, and a photodetector 16 which detects an up-conversion signal beam A converted from a terahertz wave 3 emitted perpendicularly from the light output surface 12b. The slanted periodically poled device 12 is configured to generate the up-conversion signal beam A in the same direction as and in parallel with the pump beam 1 by quasi phase matching between the terahertz wave 3 perpendicularly incident from the terahertz wave input surface 12c and the pump beam 1.

Abstract: An object of the present invention is to produce a non-conventional high-quality BNA single crystal. Another object of the present invention is to provide a process for producing the above-described high-quality BNA single crystal. Specifically, the present invention provides a BNA crystal characterized by having a half-value width of diffraction peak X-ray intensity of 100 seconds or less in a rocking curve measurement by X-ray diffraction method.

Abstract: The present invention includes a slanted periodically poled device 12 including a light input surface 12a and a light output surface 12b parallel to each other and a terahertz wave input surface 12c orthogonal to the light input surface 12a and the light output surface 12b, a pump beam source 14 which emits pump beam 1 perpendicularly to the light input surface 12a, and a photodetector 16 which detects an up-conversion signal beam A converted from a terahertz wave 3 emitted perpendicularly from the light output surface 12b. The slanted periodically poled device 12 is configured to generate the up-conversion signal beam A in the same direction as and in parallel with the pump beam 1 by quasi phase matching between the terahertz wave 3 perpendicularly incident from the terahertz wave input surface 12c and the pump beam 1.

Abstract: A mobility measuring apparatus includes a storage unit that respectively stores a relationship between the mobility ? of carriers in a semiconductor and a decay constant ? of the carriers and a relationship between a reflectivity R of the semiconductor to a terahertz light and the decay constant ? of the carriers, a light radiating unit that radiates a terahertz light to the semiconductor as a sample, a detecting unit that detects a reflected light of the sample to the radiated terahertz light, a reflectivity calculating unit that calculates the reflectivity Rexp of the sample by determining a ratio of an intensity of the reflected light relative to an intensity of the radiated terahertz light, an obtaining unit that obtains the decay constant ?exp of the sample corresponding to the reflectivity Rexp of the sample by making reference to the stored relationship between the reflectivity R and the decay constant ? of the carriers, and a mobility calculating unit that calculates the mobility ?exp of the sample fr

Abstract: To provide a monochromatic wavelength variable terahertz wave generation/detection system that has high detection sensitivity at room temperature and that can quickly operate at the same time, excitation light of monochromatic wavelength generated from one excitation light source is inputted to a wavelength variable terahertz wave source and a nonlinear light conversion terahertz wave detector through an excitation light phase control optical system shown below.

Abstract: An object of the present invention is to produce a non-conventional high-quality BNA single crystal. Another object of the present invention is to provide a process for producing the above-described high-quality BNA single crystal. Specifically, the present invention provides a BNA crystal characterized by having a half-value width of diffraction peak X-ray intensity of 100 seconds or less in a rocking curve measurement by X-ray diffraction method.

Abstract: A mobility measuring apparatus includes a storage unit that respectively stores a relationship between the mobility ? of carriers in a semiconductor and a decay constant ? of the carriers and a relationship between a reflectivity R of the semiconductor to a terahertz light and the decay constant ? of the carriers, a light radiating unit that radiates a terahertz light to the semiconductor as a sample, a detecting unit that detects a reflected light of the sample to the radiated terahertz light, a reflectivity calculating unit that calculates the reflectivity Rexp of the sample by determining a ratio of an intensity of the reflected light relative to an intensity of the radiated terahertz light, an obtaining unit that obtains the decay constant ?exp of the sample corresponding to the reflectivity Rexp of the sample by making reference to the stored relationship between the reflectivity R and the decay constant ? of the carriers, and a mobility calculating unit that calculates the mobility ?exp of the sample fr

Abstract: To provide a monochromatic wavelength variable terahertz wave generation/detection system that has high detection sensitivity at room temperature and that can quickly operate at the same time, excitation light of monochromatic wavelength generated from one excitation light source is inputted to a wavelength variable terahertz wave source and a nonlinear light conversion terahertz wave detector through an excitation light phase control optical system shown below.