Abstract: An ATR apparatus includes a prism having a reflection surface, a holding unit holding a sample including a suspension on the reflection surface, and an adjustment unit adjusting a fluidal state of the sample held on the reflection surface. The adjustment unit adjusts the fluidal state of the sample to a first fluidal state in order to acquire a first detection result relating to the sample in the first fluidal state and adjusts the fluidal state of the sample to a second fluidal state in order to acquire a second detection result relating to the sample in the second fluidal state.

Abstract: The optical element for a low frequency band includes a substrate including a first main face and a second main face, the substrate having birefringence, and an antireflection film located on the first main face, wherein the low frequency band is lower than a reststrahlen band of the antireflection film, wherein an absolute value of a difference between a first refractive index and a second refractive index of the substrate in the low frequency band is 0.2 or more, and wherein a thickness of the substrate is 15 ?m or more and 4000 ?m or less.

Abstract: A spectroscopic measurement device includes: a light source unit configured to output pump light and probe light; a terahertz wave generation unit configured to generate a terahertz wave by the input of the pump light; a terahertz wave detection unit to which the terahertz wave and the probe light are input and configured to modulate the probe light based on a refractive index that changes due to an electro-optical effect according to the input of the terahertz wave; and a light detection unit configured to detect the probe light modulated by the terahertz wave detection unit. A main body unit is configured to include the light source unit and the light detection unit. A measurement unit is configured to include the terahertz wave generation unit and the terahertz wave detection unit. The main body unit and the measurement unit are optically connected to each other by a polarization maintaining fiber.

Abstract: An optical kit includes a base including a main surface; and a holding unit provided on the main surface to hold an optical system. The holding unit includes a lens holding unit that holds a lens, a reflector holding unit that holds a corner reflector, a first aperture member holding unit that holds a first aperture member, a second aperture member holding unit that holds a second aperture member, and a third aperture member holding unit that holds a third aperture member. The reflector holding unit includes a first mechanism that holds an entirety of the corner reflector so as to be rotatable along the main surface, and a second mechanism configured to adjust an optical axis of a diffracted light in each of a reflective diffraction grating and a mirror.

Abstract: An optical element for terahertz waves includes: an optical component including a silicon surface, an antireflection film including an organic resin including a cycloolefin-based polymer as a main component, and inorganic particles dispersed in the organic resin; and an adhesive layer located between the optical component and the antireflection film in a thickness direction of the antireflection film and bonding the silicon surface of the optical component and the antireflection film to each other. The adhesive layer includes a thermally denatured olefin-based polymer.

Abstract: An optical element includes a laminate including a first refractive index layer and a second refractive index layer having different refractive index for terahertz waves, wherein the laminate includes a pair layer group in which a plurality of pair layers including the first refractive index layer and the second refractive index layer are laminated, wherein the thickness of the first refractive index layer and the thickness of the second refractive index layer are each smaller than a wavelength of the terahertz waves, and wherein each of the pair layers has a predetermined effective refractive index for the terahertz waves depending on a thickness ratio between the first refractive index layer and the second refractive index layer.

Abstract: A wave plate comprising: a prism member having an entrance surface for receiving a terahertz wave T, and an exit surface for emitting the terahertz wave T received by the entrance surface; wherein the prism member is constituted by a plurality of waveguide regions having: a partial entrance surface for receiving a part of the terahertz wave T, a plurality of total reflection surfaces for totally reflecting the terahertz wave T from the partial entrance surface, and a partial exit surface for emitting the terahertz wave T totally reflected from the total reflection surfaces; and each of the partial entrance surfaces combine to constitute the entrance surface of the prism member, and each of the partial exit surfaces combine to constitute the exit surface of the prism member, by stacking waveguide regions.

Abstract: A measurement auxiliary member is placed on an arrangement surface of a prism. A measurement object is placed on an upper surface of the measurement auxiliary member. The measurement auxiliary member totally reflects the terahertz wave input from a lower surface by the upper surface and outputs the totally-reflected terahertz wave from the lower surface. A main pulse of a terahertz wave totally reflected by the upper surface of the measurement auxiliary member without multiply-reflected inside any optical element on an optical path of the terahertz wave, and a noise pulse of a terahertz wave multiply-reflected inside any optical element on the optical path and reflected on an interface between the prism and the measurement auxiliary member, are temporally separated from each other when detecting a correlation by a terahertz wave detection element.

Abstract: An optical measurement device includes a light source configured to output a terahertz wave and coaxial light having a wavelength different from the wavelength of the terahertz wave, coaxially with the terahertz wave; an intensity modulation unit configured to perform intensity modulation of at least the terahertz wave of the terahertz wave and the coaxial light in a predetermined modulation frequency; and a light detection unit configured to synchronously detects each of the terahertz wave and the coaxial light which have acted on a measurement subject via the intensity modulation unit based on the modulation frequency.

Abstract: In an optical analysis device, a terahertz wave generation module includes a terahertz wave generation unit, and a polarization switching unit that periodically switches a polarization state of a terahertz wave between a first polarization state and a second polarization state that are different from each other on the basis of a frequency signal. An electric field vector measurement unit detects a first electric field vector of a terahertz wave in a first polarization state and a second electric field vector of the terahertz wave in a second polarization state by referring to a frequency signal.

Abstract: A wave plate comprising: a prism member having an entrance surface for receiving a terahertz wave T, and an exit surface for emitting the terahertz wave T received by the entrance surface; wherein the prism member is constituted by a plurality of waveguide regions having: a partial entrance surface for receiving a part of the terahertz wave T, a plurality of total reflection surfaces for totally reflecting the terahertz wave T from the partial entrance surface, and a partial exit surface for emitting the terahertz wave T totally reflected from the total reflection surfaces; and each of the partial entrance surfaces combine to constitute the entrance surface of the prism member, and each of the partial exit surfaces combine to constitute the exit surface of the prism member, by stacking waveguide regions.

Abstract: An optical element for terahertz waves includes: an optical component including a silicon surface, an antireflection film including an organic resin including a cycloolefin-based polymer as a main component, and inorganic particles dispersed in the organic resin; and an adhesive layer located between the optical component and the antireflection film in a thickness direction of the antireflection film and bonding the silicon surface of the optical component and the antireflection film to each other. The adhesive layer includes a thermally denatured olefin-based polymer.

Abstract: A wave plate comprising: a prism member having an entrance surface for receiving a terahertz wave T, and an exit surface for emitting the terahertz wave T received by the entrance surface; wherein the prism member is constituted by a plurality of waveguide regions having: a partial entrance surface for receiving a part of the terahertz wave T, a plurality of total reflection surfaces for totally reflecting the terahertz wave T from the partial entrance surface, and a partial exit surface for emitting the terahertz wave T totally reflected from the total reflection surfaces; and each of the partial entrance surfaces combine to constitute the entrance surface of the prism member, and each of the partial exit surfaces combine to constitute the exit surface of the prism member, by stacking waveguide regions.

Abstract: A tunnel current control apparatus includes a terahertz wave generation element configured to generate and output a terahertz wave pulse, a CEP adjustment unit configured to adjust a CEP of the terahertz wave pulse, and an off-axis parabolic mirror serving as a focusing element configured to focus the terahertz wave pulse in a gap between a first conductive object and a second conductive object. The CEP adjustment unit can arbitrarily adjust the CEP of the terahertz wave pulse.

Abstract: A tunnel current control apparatus includes a light source, a branching unit, a chopper, an optical path difference adjustment unit, a polarizer, a terahertz wave generation element, a CEP adjustment unit, a terahertz wave detection element, a quarter-wave plate, a polarization separation element, photodetectors, a differential amplifier, a lock-in amplifier, a current measurement unit, a processing unit, mirrors, and off-axis parabolic mirrors. The CEP adjustment unit can arbitrarily adjust a CEP of a terahertz wave pulse. The processing unit obtains a conversion filter used for conversion from an electric field waveform of a far field of the terahertz wave pulse to an electric field waveform of a near field based on a tunnel current measured by the current measurement unit and a correlation detected by the terahertz wave detection element.

Abstract: An optical measurement device includes a light source configured to output a terahertz wave and coaxial light having a wavelength different from the wavelength of the terahertz wave, coaxially with the terahertz wave; an intensity modulation unit configured to perform intensity modulation of at least the terahertz wave of the terahertz wave and the coaxial light in a predetermined modulation frequency; and a light detection unit configured to synchronously detects each of the terahertz wave and the coaxial light which have acted on a measurement subject via the intensity modulation unit based on the modulation frequency.

Abstract: In an optical analysis device, a terahertz wave generation module includes a terahertz wave generation unit, and a polarization switching unit that periodically switches a polarization state of a terahertz wave between a first polarization state and a second polarization state that are different from each other on the basis of a frequency signal. An electric field vector measurement unit detects a first electric field vector of a terahertz wave in a first polarization state and a second electric field vector of the terahertz wave in a second polarization state by referring to a frequency signal.

Abstract: Disclosed is a non-linear optical crystal containing pyridinium represented by the following Formula (1), 4-substituted phenylsulfonate represented by the following Formula (2a), and 2,4,6-substituted phenylsulfonate represented by the following Formula (2b).

Abstract: A tunnel current control apparatus includes a terahertz wave generation element configured to generate and output a terahertz wave pulse, a CEP adjustment unit configured to adjust a CEP of the terahertz wave pulse, and an off-axis parabolic mirror serving as a focusing element configured to focus the terahertz wave pulse in a gap between a first conductive object and a second conductive object. The CEP adjustment unit can arbitrarily adjust the CEP of the terahertz wave pulse.

Abstract: A tunnel current control apparatus includes a light source, a branching unit, a chopper, an optical path difference adjustment unit, a polarizer, a terahertz wave generation element, a CEP adjustment unit, a terahertz wave detection element, a quarter-wave plate, a polarization separation element, photodetectors, a differential amplifier, a lock-in amplifier, a current measurement unit, a processing unit, mirrors, and off-axis parabolic mirrors. The CEP adjustment unit can arbitrarily adjust a CEP of a terahertz wave pulse. The processing unit obtains a conversion filter used for conversion from an electric field waveform of a far field of the terahertz wave pulse to an electric field waveform of a near field based on a tunnel current measured by the current measurement unit and a correlation detected by the terahertz wave detection element.