Riken Corporation

Ricoh Company, Ltd.

Mitsubishi Heavy Industries Limited

Topcon Corporation

Furukawa Co., Ltd.

Hiroaki Minamide

Hiromasa Ito

Kouji Nawata

Yuichiro Kamino

Yasuhiro Higashi

Toshiyuki Ikeoh

Syusaku Yamamoto

Yoshikiyo Moriguchi

Takumi Satoh

Yoshio Wada

Tomofumi Ikari

Akihide Hamano

Seigo Ohno

Mikiko Saito

Takashi Notake

Ruixiang Guo

Koji Nawata

Shuzhen Fan

Yu Tokizane

Feng Qi

Keisuke Kajikawa

Yuma Takida

Shin'ichiro Hayashi

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.

Inspection device

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.

Terahertz wave generation method and terahertz wave generation device

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 deviceprovided with a pump light sourcethat generates pump light LP of a single wavelength and a nonlinear optical element (periodical polarization inversion element). The nonlinear optical element has a periodic structure in which the polarization or the crystal orientation is periodically inverted with a certain inversion period &#x39b;. When the pump light enters the nonlinear optical element, idler light LI and signal light Lare generated. The idler light and the signal light satisfy the law of conservation of energy for the pump light and a collinear phase matching condition for a virtual pump light wave vector k'obtained by vector addition or subtraction of a grating vector kwhich corresponds to the inversion period, to or from a pump light wave vector kin the nonlinear optical element. The embodiment of the present invention also provides an optical parametric amplifier, a terahertz wave detector, and a nonlinear optical element.

Terahertz wave generating device, optical parametric amplifier, terahertz wave detector, and nonlinear optical element

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 (&#x3c9;) and different oscillation timings (t) in one excitation process of the excitation light source, an oscillation frequency difference (&#x394;&#x3c9;) 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.

Pulsed electromagnetic-wave generator and measuring apparatus

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.

Optical response measuring device and optical response measuring method

The present invention includes a slanted periodically poled deviceincluding a light input surfaceand a light output surfaceparallel to each other and a terahertz wave input surfaceorthogonal to the light input surfaceand the light output surface, a pump beam sourcewhich emits pump beamperpendicularly to the light input surface, and a photodetectorwhich detects an up-conversion signal beam A converted from a terahertz waveemitted perpendicularly from the light output surface. The slanted periodically poled deviceis configured to generate the up-conversion signal beam A in the same direction as and in parallel with the pump beamby quasi phase matching between the terahertz waveperpendicularly incident from the terahertz wave input surfaceand the pump beam

Terahertz wave detection device and method

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.

BNA crystal

A mobility measuring apparatus includes a storage unit that respectively stores a relationship between the mobility &#x3bc; of carriers in a semiconductor and a decay constant &#x3b3; of the carriers and a relationship between a reflectivity R of the semiconductor to a terahertz light and the decay constant &#x3b3; 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 Rof 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 &#x3b3;of the sample corresponding to the reflectivity Rof the sample by making reference to the stored relationship between the reflectivity R and the decay constant &#x3b3; of the carriers, and a mobility calculating unit that calculates the mobility &#x3bc;of the sample from the stored relationship between the mobility &#x3bc; and the decay constant &#x3b3; on the basis of the obtained decay constant &#x3b3;.

Mobility measuring apparatus, method therefor, and resistivity measuring apparatus and method therefor

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. The excitation light phase control optical system includes, on a light path of the excitation light, an optical element capable of simultaneously changing an incidence angle of the excitation light to a generation point of a terahertz wave in the wavelength variable terahertz wave source and an incidence angle of the excitation light to an incidence point of the terahertz wave in the nonlinear light conversion terahertz wave detector to set both the generation point and the incidence point at the same time on the focal points in a confocal optical system.

Monochromatic wavelength variable terahertz wave generation/detection system and method

A method and an apparatus for generating a terahertz wave, wherein one end faceof a non-linear optical crystalis positioned approximately orthogonally to a direction of generation of a terahertz wave, pump lightand idler lightare totally reflected at an approximately same pointon the end face, and the generated terahertz waveis emitted roughly vertically to the end face.

Growing community of inventors

Wako, Japan

Hiroaki Minamide