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 device 100 provided with a pump light source 104 that generates pump light LP of a single wavelength and a nonlinear optical element (periodical polarization inversion element) 102. The nonlinear optical element has a periodic structure in which the polarization or the crystal orientation is periodically inverted with a certain inversion period . When the pump light enters the nonlinear optical element, idler light LI and signal light L.sub.THz are 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.sub.p obtained by vector addition or subtraction of a grating vector k.sub. which corresponds to the inversion period, to or from a pump light wave vector k.sub.p in 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.

A liquid crystal photoelectric apparatus includes a first and a second quartz glass substrates, an upper alignment layer disposed between the first and the second quartz glass substrates, a lower alignment layer disposed between the upper alignment layer and the second quartz glass substrate, a liquid crystal material disposed between the upper and the lower alignment layers, a first transparent conductive layer disposed between the upper alignment layer and the first quartz glass substrate and including at least one first main portion and first finger portions extending from the corresponding first main portion and a second transparent conductive layer second transparent conductive layer disposed between the lower alignment layer and the second quartz glass substrate and including a second main portion and second finger portions extending from the second main portion in an extension direction perpendicular to that of the first finger portions. An optical imaging processing system is provided.

An apparatus for generation of coherent terahertz radiation is provided. In one example, the apparatus includes one or more multilayer tunable microcolumns. In turn, a multilayer tunable microcolumn can include a substrate, a bottom electrode, a bottom layer of a ferromagnetic material further comprising a magnon gain medium (MGM) coupled to the bottom electrode, a tunnel junction coupled to the ferromagnetic material, a spin injector coupled to the tunnel junction, a pinning layer coupled to the spin injector, a reference layer coupled to the pinning layer and a top electrode. In one example, a containment cavity encloses at least one of the multilayer tunable microcolumns. In one example, a storage cavity encloses the containment cavity.

A system passively images a scene using an antenna for collecting electromagnetic energy from the scene and directing the electromagnetic energy toward a single pixel sensor. A spatial light modulator includes a flexible tape that supports a series of blocking patterns along its length. The tape moves through the electromagnetic energy in an exposure region as the energy travels from the antenna to the sensor and the tape moves on a transport path that is nonlinear outside of the exposure region. A processor captures a set of output values from the sensor to form an image of the scene based on the set of output values. Two blocking pattern structures, either rigid or flexible, can be superimposed in an exposure region between an antenna and a sensor.

One aspect of the present disclosure provides a terahertz-wave detector including a semiconductor substrate, an active element formed on the semiconductor substrate and a first resistive portion electrically connected in parallel with the active element.

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.

Disclosed are a measuring apparatus and a substrate analysis method using the same. The measuring apparatus includes a light source that generates a laser beam, a beam splitter that splits the laser beam into a probe laser beam and a reference laser beam, an antenna that receives the probe laser beam to produce a terahertz beam, an electro-optical device that receives the reference laser beam and the terahertz beam to change a vertical polarization component and a horizontal polarization component of the reference laser beam, based on intensity of the terahertz beam, and a streak camera that obtains a time-domain signal corresponding to a ratio between the vertical polarization component and the horizontal polarization component.

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 device 100 provided with a pump light source 104 that generates pump light LP of a single wavelength and a nonlinear optical element (periodical polarization inversion element) 102. The nonlinear optical element has a periodic structure in which the polarization or the crystal orientation is periodically inverted with a certain inversion period . When the pump light enters the nonlinear optical element, idler light LI and signal light L.sub.THz are 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.sub.p obtained by vector addition or subtraction of a grating vector k.sub. which corresponds to the inversion period, to or from a pump light wave vector k.sub.p in 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.

Provided is a terahertz light source device including an antenna, a plurality of wire electrodes configured to connect the antenna to a power source, a capacitor connected to the wire electrodes between the antenna and the power source, and a plurality of resonance tunneling diodes connected to the wire electrodes between the capacitor and the antenna, and configured to generate a terahertz wave by coupling with the capacitor as a parallel resonance circuit with respect to the power source.

A method of making an optical device including forming a plurality of holes with varying radii milled vertically into a film, wherein said holes form a pattern. The radius of each hole determines an effective refractive index for said hole. The effective refractive index modifies a phase and an intensity of an incoming electromagnetic radiation as the radiation propagates through said hole. The device is configured to be operating equally for each linearly polarized radiation simultaneously, wherein the each linearly polarized radiation is normally incident on the device.