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: 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: Provided is a semiconductor device including: a semiconductor element arranged on a substrate and having two electrodes; a conductive strip in contact with one of the two electrodes; and a dielectric arranged between another one of the two electrodes and the conductive strip, in which the conductive strip has an opening formed therein, the dielectric has a void formed therein, and the opening and the void are connected to each other.

Abstract: Provided is a diode element, a detecting device, and the like which solve problems of a conventional lateral diode element. In the conventional element, a semiconductor interface appears in current path between two electrodes on a surface thereof, and thus noise caused by the interface is large. The diode element includes: a first-conductive-type low carrier concentration layer; a first-conductive-type high carrier concentration layer; and a Schottky electrode and an ohmic electrode which are formed on a semiconductor surface. The low carrier layer has a carrier concentration that is lower than that of the high carrier layer. The diode element includes a first-conductive-type impurity introducing region formed below the ohmic electrode, and includes a second-conductive-type impurity introducing region so as not to be in electrical contact with the Schottky electrode on the semiconductor surface between the Schottky and the ohmic.

Abstract: An oscillator configured to oscillate an electromagnetic wave, including: a negative resistance device; a microstrip resonator configured to determine an oscillation frequency of an electromagnetic wave excited by the negative resistance device; a resistance device and a capacitance device, which form a low-impedance circuit configured to suppress parasitic oscillation; and a strip conductor configured to connect the capacitance device of the low-impedance circuit and the microstrip resonator to each other, in which an inductance L of the strip conductor and a capacitance C of the microstrip resonator produce a resonance frequency of ½??LC, and ¼ of an equivalent wavelength of the resonance frequency is larger than a distance between the negative resistance device and the resistance device of the low-impedance circuit via the strip conductor, is provided.

Abstract: Provided is a method of calculating a refractive index of at least a part of a specimen by using electromagnetic wave measurement, the method including: measuring a first scattered wave from a structure of the specimen; measuring a second scattered wave from a structure in which a material for calculating refractive index is disposed on a surface of the specimen; and comparing intensities at corresponding portions of the first scattered wave and the second scattered wave.

Abstract: An electromagnetic wave generating device is provided which includes an optical waveguide including a plurality of waveguide segments such that the main lobe of a combined electromagnetic wave has a substantially single large directivity. The electromagnetic wave generating device includes the optical waveguide including a plurality of waveguide segments each of which is sandwiched between dielectrics and includes a nonlinear optical crystal. The waveguide segments are arranged such that an angle formed by the directions of propagation of light in the two adjacent waveguide segments substantially corresponds to 2?c. When ng denotes the refractive index of the nonlinear optical crystal for light and ?eff denotes the effective relative permittivity of an assembly of the dielectrics and the waveguide segments for an electromagnetic wave, ?c is defined as ?c=cos?1 (ng/???eff).

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: An oscillation device for oscillating a terahertz wave includes a substrate, an active layer which is provided on an upper portion of the substrate and which generates a terahertz wave by intersubband transition of carrier, and a luminous layer which is provided on an upper portion of the substrate and which generates light by interband transition of carrier. In addition, the luminous layer is arranged at a position at which the light generated in the luminous layer can radiate on the active layer.

Abstract: An oscillator includes a resonator section structured such that a dielectric is interposed between first and second conductors and such that the first and second conductors are electrically connected to a resonant tunneling diode, a capacitor section structured such that the dielectric is interposed between the first and second conductors, a line section configured to electrically connect the resonator section and the capacitor section in parallel to each other, and a resistor section configured to electrically connect the first and second conductors to each other. A first position of the resonator section and a second position of the capacitor section are connected to each other by the line section so that the first position and the second position are substantially electrically equivalent to each other in a wavelength range larger than a wavelength of an electromagnetic wave that resonates in the resonator section.

Abstract: To provide a resonator that includes a resonant tunneling diode. A resistor layer provided in series with the resonant tunneling diode, a dielectric provided in contact with the resonant tunneling diode, and first and second conductors that are placed so that the resonant tunneling diode and the dielectric are sandwiched therebetween are provided. Further, a resonator area where the dielectric is sandwiched between the first and second conductors, and a resistor area where the resonant tunneling diode and the resistor layer are sandwiched between the first and second conductors are provided in parallel with each other.

Abstract: There is provided a photoconductive element capable of increasing an output and detection sensitivity by increasing resistivity as the entire element. The photoconductive element is a photoconductive element capable of generating or detecting an electromagnetic wave when light is emitted thereto. The photoconductive element includes a photoconductive layer having a semiconductor layer whose resistivity changes when light is emitted to thereby generate or detect an electromagnetic wave; and a plurality of electrodes provided in contact with the semiconductor layer. The resistivity of the semiconductor layer changes in a thickness direction of intersecting a surface of the semiconductor layer contacting the electrodes. Assuming that the semiconductor layer includes a first region and a second region which is farther away from the electrodes in the thickness direction than the first region, the resistivity in the first region is greater than the resistivity in the second region.

Abstract: An oscillation circuit including: a negative resistance element; a resonance circuit connected to the negative resistance element; and a stabilization circuit connected in parallel with the negative resistance element to suppress parasitic oscillation, wherein the stabilization circuit includes a variable shunt resistor and a adjusting device for adjusting the shunt resistor.

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: 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: An oscillator which oscillates electromagnetic waves includes a negative differential resistance element, a resonator configured to prescribe oscillation frequencies of the electromagnetic waves, a voltage modulation unit configured to modulate the negative differential resistance element, a stabilizing circuit configured to suppress parasitic oscillation, and a bias circuit, including a power supply and a line, used to control an operating point voltage of the negative differential resistance element. The voltage modulation unit is connected to the bias circuit through the stabilizing circuit.

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: To provide a resonator that includes a resonant tunneling diode that can generate an electromagnetic wave. In the resonator, the resonant tunneling diode and a resistor layer are sandwiched between first and second conductors in a direction approximately perpendicular to the in-plane direction of the resonant tunneling diode. Further, the in-plane cross-sectional area of the resistor layer is larger than that of the resonant tunneling diode. Further, the width of the in-plane cross-sectional area of the resistor layer is more than twice as large as the skin depth of an electromagnetic wave to be caused to resonate.

Abstract: An oscillator includes a resonator section structured such that a dielectric is interposed between first and second conductors and such that the first and second conductors are electrically connected to a resonant tunneling diode, a capacitor section structured such that the dielectric is interposed between the first and second conductors, a line section configured to electrically connect the resonator section and the capacitor section in parallel to each other, and a resistor section configured to electrically connect the first and second conductors to each other. A first position of the resonator section and a second position of the capacitor section are connected to each other by the line section so that the first position and the second position are substantially electrically equivalent to each other in a wavelength range larger than a wavelength of an electromagnetic wave that resonates in the resonator section.