Abstract: An apparatus for acquiring information on a time waveform of a terahertz wave is comprised of a terahertz wave-generating unit, a waveform information-detecting unit, and a delay unit for changing the time after the terahertz wave is generated in the generating unit until it is detected as waveform information of the terahertz wave in the detecting unit, wherein the delay unit is configured so as to change a propagating distance of the terahertz wave generated by the generating unit, and associates waveform information of the terahertz wave, which is detected in the detecting unit, and the propagating distance every terahertz wave generated by the generating unit.

Abstract: The present invention provides a terahertz wave measuring apparatus and measurement method capable of improving the quantitativeness of obtained frequency spectrum information. In a measurement method in which a terahertz wave measuring apparatus is used, the terahertz wave measuring apparatus measures a time waveform of a terahertz wave relating to a calibration sample whose shape of a calibration spectrum is already known and obtains a measurement spectrum by transforming the time waveform. The calibration spectrum and the measurement spectrum are compared, and, on the basis of results of the comparison, time intervals of measurement data that form a time waveform are adjusted in order to calibrate the terahertz wave measuring apparatus.

Abstract: A method for acquiring an accurate time waveform of terahertz waves includes: acquiring a first time waveform by using a first delay portion with a first difference in length of the optical paths in the second delay portion, using a second delay portion to change the first difference in length of the optical paths to a second difference in length of the optical paths that is different from the first difference in length of the optical paths, acquiring a second time waveform by using the first delay portion with the second difference in length of the optical paths, adjusting the acquired first and second time waveforms in accordance with a predetermined differences in length of the optical paths based on the first and second differences in length of the optical paths, and averaging the first and second time waveforms according to the predetermined difference in length of the optical paths.

Abstract: An apparatus visualizing internal information of an object includes a detection unit of terahertz wave, a generating unit of a time waveform of the terahertz wave, a modulation unit, an adjustment unit, and an addition unit. The modulation unit sequentially performs spatial modulation on a propagation distance for each pixel of a terahertz wave corresponding to a pixel in a horizontal direction by using a plurality of modulation patterns, and emits a plurality of terahertz waves. Based on a time amount converted from the change of the propagation distances corresponding to the modulation patterns, the adjustment unit adjusts a position on a time axis of the time waveforms of a plurality of terahertz waves and calculates a new plurality of time waveforms. The addition unit adds a new time waveform for each pixel. The apparatus can suppress reduction in signal intensity of a terahertz wave while maintaining detection sensitivity.

Abstract: An analyzing apparatus includes a first optical unit that causes a terahertz wave generated by a generation unit to be condensed at a first position in an object; a second optical unit that causes the terahertz wave from the object to be condensed at a second position; a third optical unit that causes the terahertz wave condensed at the second position to be condensed at a third position; and a detection unit that detects the terahertz wave condensed at the third position. The analyzing apparatus selectively detects the terahertz wave from the first position in the object from among terahertz waves from the object.

Abstract: An apparatus for measuring a terahertz wave includes a dispersing section 103 for chirping the terahertz wave 104 generated from a generating section 101. A detecting section 102 detects waveform information on the terahertz wave chirped by the dispersing section 103. As a result, it is possible to acquire frequency information included in the waveform information. Therefore, it is possible to acquire spectral information including amplitude information of each frequency component and intensity information on each frequency or wavelength from the time waveform without Fourier-transforming the time waveform.

Abstract: An oscillator having a negative resistance device and a resonator includes: a transmission line connected to the negative resistance device, a three-terminal device including a first terminal connected to the signal line side of the transmission line at a terminal part, a second terminal connected to the grounding line side of the transmission line and a third terminal receiving a control signal applied thereto; a first regulation unit for regulating the control signal to be applied to the third terminal; and a second regulation unit for regulating the voltage to be applied to the second terminal, the first and the second regulation unit being adapted to regulate respectively the control signal and the voltage so as to make the characteristic impedance of the transmission line and the impedance between the first and the second terminal show an impedance matching. The power consumption rate of the stabilizing circuit can be reduced.

Abstract: Provided is a terahertz wave optical device that can be used as a terahertz wave generating device including: an optical switch portion for generating a carrier abruptly by irradiation with excitation light; and a first electrode portion and a second electrode portion that are disposed so as to be opposed to each other with the optical switch portion therebetween so as to apply an electric field in a thickness direction of the optical switch portion. The first electrode portion includes, at least in part, an antenna portion having an antenna function of distributing the carrier generated by the irradiation with the excitation light in a direction crossing an application direction of the electric field. With the terahertz wave optical device, a step for adjusting the incident angle of the excitation light is simplified.

Abstract: To provide new image forming apparatus and a printing method that can obtain information on image forming by using terahertz waves. An image forming apparatus includes a stock unit for stocking a media stack made of a plurality of media with images formed on; an electromagnetic wave generation unit for generating a terahertz wave to radiate on the media stack; an electromagnetic wave detection unit for detecting the terahertz wave propagated in a laminating direction of the media stack; a memory unit for storing reference data; a processing unit for generating data related to an image forming state from the detection signal from the electromagnetic wave detection unit, information on the number of sheets of the medium, and information on the image formed on the medium; and a comparative unit for comparing the data generated by the processing unit and the reference data stored in the memory unit.

Abstract: Provided are an apparatus and a method which enable acquisition of a temporal waveform of a propagating terahertz wave by changing a propagation velocity of the terahertz wave. A waveform information acquisition apparatus includes a generation portion for generating a terahertz wave, a propagation portion for allowing the terahertz wave generated by the generation portion to propagate therethrough, a detection portion for detecting waveform information of the terahertz wave, a first delay portion for changing a propagation velocity of the terahertz wave, and a control portion for controlling the first delay portion to change the propagation velocity of the terahertz wave in the propagation portion, and acquires information regarding the temporal waveform of the terahertz wave detected by the detection portion.

Abstract: A terahertz wave generation element includes a plurality of waveguides including an electro-optic crystal, and an optical coupling member for extracting a terahertz wave to the outside. The terahertz wave is generated when light propagates through the waveguides. The waveguides are arranged to be rotationally symmetric with respect to a predetermined axis. The optical coupling member is arranged so that wave fronts of the terahertz waves generated from the waveguides are matched together.

Abstract: A terahertz wave transceiver configured to generate and detect terahertz waves based on time-domain spectroscopy includes a photoconductive device having a photoconductive film, a first electrode, and a second electrode. An excitation light illumination region is formed between the first and second electrodes. A bias applying unit applies a bias between the first electrode and the second electrode to generate the terahertz wave in the excitation light illumination region. A current detection unit detects a terahertz-wave current that is a component of a current generated in the excitation light illumination region and that is generated by an electric field of a received terahertz wave arriving from the outside. A current drawing unit draws a current originating from the bias applied by the bias applying unit. An adjustment unit determines the amount of the current drawn, based on the amount of the bias applied by the bias applying unit.

Abstract: A terahertz-wave generating device including an optical waveguide containing an electrooptic crystal includes: first and second optical waveguides through which first and second light beams respectively propagate; a propagation portion through which a first terahertz wave propagates, the first terahertz wave being generated from the second optical waveguide in a direction different from a direction of the second light beam; and a delay portion arranged at incidence sides of the first and second light beams and configured to delay the first light beam relative to the second light beam. The first optical waveguide and the second optical waveguide are arranged with the propagation portion interposed therebetween. A first equiphase surface of the first terahertz wave is substantially aligned with a second equiphase surface of a second terahertz wave generated from the first optical waveguide in a direction different from a direction of the first light beam.

Abstract: A photoconductive element for generating or detecting a terahertz wave comprises a carrier generation layer for generating carriers on light irradiation, a pair of conductive electrodes provided in opposition on one face of the carrier generation layer, each containing a strip line, a pair of conductive antennas placed in opposition with a gap for light irradiation onto the carrier generation layer, each being joined to the electrodes, a pair of conductive adjusting stubs for adjusting a propagation state of the terahertz wave generated or detected by the carriers, wherein each of the adjusting stubs has a length of not longer than the wavelength ? of the terahertz wave generated by the carriers, and is placed at a distance of not more than the wavelength ? from a joint between the antenna and the electrode.

Abstract: A time-domain waveform of a terahertz wave is measured by a method based on time-domain spectroscopy by using an optical delay unit to adjust an optical path length along which excitation light propagates thereby adjusting a difference between a time at which the excitation light arrives at a generating unit configured to generate the terahertz wave and a time at which the excitation light arrives at a detection unit configured to detect the terahertz wave. The optical delay unit is driven according to a first speed pattern to acquire a first time-domain waveform. The optical delay unit is then driven according to a second speed pattern different from the first speed pattern to acquire a second time-domain waveform. The first time-domain waveform and the second time-domain waveform are averaged.

Abstract: In a measurement of a time-domain waveform of a terahertz wave based on time-domain spectroscopy, a current signal including a component originating from the terahertz wave is detected using a photoconductive device, and a voltage signal corresponding to the detected current signal is detected. At a pre-processing stage before the voltage signal detection, an offset current included in the detected current signal and having no relation to the terahertz wave is drawn. The offset current is monitored and the magnitude of the drawn offset current is adjusted according to a result of the monitoring. A time-domain waveform of the terahertz wave is acquired based on the voltage signal detected while drawing the offset current. The monitoring of the offset current and the adjusting of the offset current are performed in a waiting state in which measurement of the time-domain waveform of the terahertz wave is not performed.

Abstract: An analyzing apparatus includes a first optical unit that causes a terahertz wave generated by a generation unit to be condensed at a first position in an object; a second optical unit that causes the terahertz wave from the object to be condensed at a second position; a third optical unit that causes the terahertz wave condensed at the second position to be condensed at a third position; and a detection unit that detects the terahertz wave condensed at the third position. The analyzing apparatus selectively detects the terahertz wave from the first position in the object from among terahertz waves from the object.

Abstract: A detection apparatus and an imaging apparatus are capable of accurately conducting non-destructive observation of a target by using an incoherent electromagnetic wave. The detection apparatus has a generating section, a first coupler section, a delaying section, a second coupler section and a signal processing section. The generating section 101 includes a coherent electromagnetic wave source 102 and a diffusing section 103 for generating a pseudoincoherent electromagnetic wave by changing a propagation state of the coherent electromagnetic wave in accordance with a code pattern. The incoherent electromagnetic wave is split into first and second waves and the first wave is affected by the target of observation while the second wave is delayed by the delaying section. The first and second waves are then coupled to produce a coupled wave having a correlation signal of them and the signal is utilized to acquire information on the inside of the target of observation.

Abstract: A transmission line for propagating a terahertz wave generated based on a carrier generated in a carrier generation layer includes a first region in which the terahertz wave propagates in a first direction and a second region having a different impedance compared to the first region and forming a reflection interface with respect to a terahertz wave which propagates opposite to the first direction. The transmission line is formed so that a distance from an irradiation location at which light is irradiated to the carrier generation layer to the reflection interface is smaller than D, where D is a distance converted from a half width of a time waveform of a terahertz wave which propagates in the first direction without passing through the reflection interface. Accordingly, a terahertz wave can be made to propagate with energetic efficiency, to a direction the terahertz wave is required to propagate.

Abstract: An inspection apparatus for acquiring information on a measurement object using electromagnetic waves, comprising a substrate; a transmission line that is formed on the substrate; an electromagnetic wave generating unit for supplying an electromagnetic wave to the transmission line; an electromagnetic wave detecting unit for detecting the electromagnetic wave that has propagated through the transmission line; and a walled structure. The walled structure includes a side wall portion that extends along the transmission line within a region in which the electromagnetic wave that propagates through the transmission line and the measurement object interact with each other.