Abstract: A terahertz-wave generating element includes a waveguide including an electro-optic crystal; an optical coupling member that extracts a terahertz wave, which is generated from the electro-optic crystal as a result of light propagating through the waveguide, to a space; and at least two electrodes that cause a first-order electro-optic effect in the electro-optic crystal by applying an electric field to the waveguide so as to change a propagation state of the light propagating through the waveguide. A crystal axis of the electro-optic crystal of the waveguide is set such that the terahertz wave generated by a second-order nonlinear optical process and the light propagating through the waveguide are phase-matched.

Abstract: To acquire information of a test body by irradiating the test body with a terahertz wave, an information acquiring apparatus includes a photoconductive device, a terahertz wave irradiating unit, a terahertz wave irradiating unit, a detecting unit, and a light irradiating unit. The photoconductive device generates the terahertz wave by light incident from a light source. The terahertz wave irradiating unit separates the terahertz wave generated by the photoconductive device and light transmitting through, or reflecting from, the photoconductive device, and irradiates the test body with the separated terahertz wave. The detecting unit detects the terahertz wave from the test body. The light irradiating unit irradiates the detection unit with the light separated by the terahertz wave irradiating unit.

Abstract: The present invention provides an apparatus and a method for transforming a time waveform of an electromagnetic wave into a time waveform suited for signal processing and the like so as to measure the time waveform. A wavelet transform is performed on a first time waveform of an electromagnetic wave, such as a terahertz wave, measured in advance, and a second time waveform suited for signal processing and having a high correlation with a mother wavelet used in the wavelet transform is formed by controlling a wavelet expansion coefficient. In a second measurement process and onward of a target object, a transforming unit, such as a bias voltage controller, is used to transform the electromagnetic wave into a transformed time waveform so as to measure the time waveform.

Abstract: A terahertz wave generation element is provided, which includes: an optical waveguide including a core of electro-optic crystal; an optical coupler for extracting a terahertz wave generated from the optical waveguide when light propagates in the optical waveguide to a space; and a reflecting layer disposed on the opposite side to the optical coupler with respect to the core of the optical waveguide, so as to reflect the generated terahertz wave. According to the element, it is possible to provide a generation element that can generate a relatively high intensity terahertz wave efficiently by photoexcitation or generate a terahertz wave having a relatively narrow pulse width, so as to flexibly control waveform shaping of the generated terahertz wave.

Abstract: A terahertz-wave element includes a waveguide (2, 4, 5) that includes an electro-optic crystal and allows light to propagate therethrough, and a coupling member (7) that causes a terahertz wave to enter the waveguide (2, 4, 5). The propagation state of the light propagating through the waveguide (2, 4, 5) changes as the terahertz wave enters the waveguide (2, 4, 5) via the coupling member (7).

Abstract: A method of manufacturing photo-semiconductor device that has a photoconductive semiconductor film provided with electrodes and formed on a second substrate, the semiconductor film being formed by epitaxial growth on a first semiconductor substrate different from the second substrate, the second substrate being also provided with electrodes, the electrodes of the second substrate and the electrodes of the photoconductive semiconductor film being held in contact with each other.

Abstract: To provide an electromagnetic pulse transmitting apparatus and a tomography apparatus capable of shortening an electromagnetic pulse. The apparatus performs processing such that two electromagnetic pulse portions emitted to an object have an electric field intensity of mutually opposite polarity and the time difference between pulse peaks of the two electromagnetic pulse portions is a time difference within a time of a pulse width.

Abstract: A terahertz wave generation element is provided, which includes: an optical waveguide including a core of electro-optic crystal; an optical coupler for extracting a terahertz wave generated from the optical waveguide when light propagates in the optical waveguide to a space; and a reflecting layer disposed on the opposite side to the optical coupler with respect to the core of the optical waveguide, so as to reflect the generated terahertz wave. According to the element, it is possible to provide a generation element that can generate a relatively high intensity terahertz wave efficiently by photoexcitation or generate a terahertz wave having a relatively narrow pulse width, so as to flexibly control waveform shaping of the generated terahertz wave.

Abstract: A terahertz-wave element includes a waveguide (2, 4, 5) that includes an electro-optic crystal and allows light to propagate therethrough, and a coupling member (7) that causes a terahertz wave to enter the waveguide (2, 4, 5). The propagation state of the light propagating through the waveguide (2, 4, 5) changes as the terahertz wave enters the waveguide (2, 4, 5) via the coupling member (7).

Abstract: A sensor device has an optical waveguide containing an electro-optic crystal for propagating light, a coupler provided adjacent to the optical waveguide to propagate a terahertz wave generated from the electro-optic crystal as a result of the propagation of light in the optical waveguide, and a detector for detecting the terahertz wave propagating through the coupler or the light propagating through the optical waveguide. The terahertz wave is totally reflected in a section of the coupler opposite to a section where the coupler is adjacent to the optical waveguide while passing through and propagating in the optical waveguide, and in the total reflection section, the terahertz wave interacts with a subject placed close to the total reflection section.

Abstract: An apparatus includes an emitter unit configured to irradiate an object under observation with a terahertz wave, a receiver unit configured to receive a reflected terahertz wave returning from the object under observation, and a data processing unit configured to calculate a propagation time period spent in a propagation of the terahertz wave from the emitter unit to the receiver unit based on a signal received by the receiver unit and calculate a location of an abnormal tissue in the object under observation based on the propagation time period.

Abstract: A terahertz-wave element includes a waveguide (2, 4, 5) that includes an electro-optic crystal and allows light to propagate therethrough, and a coupling member (7) that causes a terahertz wave to enter the waveguide (2, 4, 5). The propagation state of the light propagating through the waveguide (2, 4, 5) changes as the terahertz wave enters the waveguide (2, 4, 5) via the coupling member (7).

Abstract: A method of manufacturing a photo-semiconductor device that has a photoconductive semiconductor film provided with electrodes and formed on a second substrate, the semiconductor film being formed by epitaxial growth on a first semiconductor substrate different from the second substrate, the second substrate being also provided with electrodes, and the electrodes of the second substrate and the electrodes of the photoconductive semiconductor film being held in contact with each other.

Abstract: To provide an electromagnetic pulse transmitting apparatus and a tomography apparatus capable of shortening an electromagnetic pulse. The apparatus performs processing such that two electromagnetic pulse portions emitted to an object have an electric field intensity of mutually opposite polarity and the time difference between pulse peaks of the two electromagnetic pulse portions is a time difference within a time of a pulse width.

Abstract: Provided is a photoconductive element which solves a problem inherent in an element for generating/detecting a terahertz wave by photoexcitation that terahertz wave generation efficiency is limited by distortions and defects of a low temperature grown semiconductor. The photoconductive element includes: a semiconductor substrate; a semiconductor low temperature growth layer; and a semiconductor layer, which is positioned between the semiconductor low temperature growth layer and the semiconductor substrate and is thinner than the semiconductor low temperature growth layer, in which the semiconductor low temperature growth layer includes a semiconductor which lattice-matches with the semiconductor layer and does not lattice-match with the semiconductor substrate.

Abstract: A laser device comprises a waveguide including a resonance structure for causing electromagnetic waves to resonate. The waveguide by turn comprises a gain medium for generating electromagnetic waves, a first negative permittivity medium arranged electrically in contact with the gain medium, a second negative permittivity medium arranged electrically in contact with the gain medium at the side opposite to the first negative permittivity medium so as to dispose the gain medium between the first and second negative permittivity mediums, and lateral structures of a positive permittivity medium arranged to be in contact with lateral surfaces of the gain medium and sandwiched between the first and second negative permittivity mediums. The waveguide has a section in which the width w of the gain medium sandwiched between the lateral structures is not greater than twice of the thickness h of the lateral structures sandwiched between the first and second negative permittivity mediums.

Abstract: The invention provides an electromagnetic wave generation device. The device includes a substrate provided with a terahertz wave oscillation section including a resonant tunneling diode structure, a two-dimensional electron layer having a semiconductor heterojunction structure, and a transistor section including a source electrode and a drain electrode provided at end portions of the two-dimensional electron layer and a gate electrode provided above the two-dimensional electron layer. The terahertz wave output of the terahertz wave oscillation section changes distribution of electrons in the two-dimensional electron layer.

Abstract: An oscillator has a negative resistance element and a resonator along with a capacitor electrically connected in parallel with the negative resistance element relative to a power bias circuit, a capacitance of the capacitor being so selected as to suppress any parasitic oscillation due to the power bias circuit and allow oscillation at a resonance frequency due to the negative resistance element and the resonator.

Abstract: The present invention provides a wavefront measuring apparatus and method, and object measuring apparatus which can increase resolution of wavefronts of electromagnetic wave pulses without being limited by the number of detecting elements. An embodiment of the present invention includes a detecting part detecting electric field strength of an electromagnetic wave pulse, and an optical delaying part delaying the electromagnetic wave pulse so as to provide a first propagation path and a second propagation path provided in a spatial region different from a spatial region of the first propagation path and having a length different from a length of the first propagation path, wherein time waveforms of the electromagnetic wave pulse are constructed using a signal associated with the electric field strength detected by the detecting part, and a wavefront is obtained based on the time waveforms and information associated with the lengths of the first and second propagation paths.

Abstract: An optical element includes a semiconductor layer having an energy band gap larger than a photon energy of light, and a plurality of electrodes in electrical contact with the semiconductor layer. At least one of the electrodes forms a Schottky junction between the electrode and the semiconductor layer; the Schottky junction has a barrier height smaller than the photon energy of the light. At least part of a junction surface between the electrode that forms the Schottky junction and the semiconductor layer includes a light irradiation surface arranged to be irradiated with the light from a surface of the semiconductor layer without the electrodes, and a portion of a coupling structure arranged to be coupled to a terahertz wave that is generated or detected through the irradiation with the light.