Riken Corporation

Ricoh Company, Ltd.

Kouji Nawata

Hiroaki Minamide

Hiromasa Ito

Yasuhiro Higashi

Toshiyuki Ikeoh

Yoshio Wada

Takumi Satoh

Shuzhen Fan

Feng Qi

Yu Tokizane

Shin'ichiro Hayashi

Yuma Takida

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 deviceprovided with a pump light sourcethat generates pump light LP of a single wavelength and a nonlinear optical element (periodical polarization inversion element). The nonlinear optical element has a periodic structure in which the polarization or the crystal orientation is periodically inverted with a certain inversion period &#x39b;. When the pump light enters the nonlinear optical element, idler light LI and signal light Lare 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'obtained by vector addition or subtraction of a grating vector kwhich corresponds to the inversion period, to or from a pump light wave vector kin 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.

Terahertz wave generating device, optical parametric amplifier, terahertz wave detector, and nonlinear optical element

A pulsed electromagnetic-wave generator includes an excitation light source, a laser resonator, a pulse generating unit, and a wavelength converting unit. Excitation light from the excitation light source enters the laser resonator. The pulse generating unit is configured to generate a pulsed light group including at least two or more pulses with different frequencies (&#x3c9;) and different oscillation timings (t) in one excitation process of the excitation light source, an oscillation frequency difference (&#x394;&#x3c9;) between the pulses in the pulsed light group being an integral multiple of a Free Spectral Range (FSR) of the laser resonator. The pulsed light group enters the wavelength converting unit. The wavelength converting unit is configured to generate a pulsed electromagnetic wave in which a wavelength of each pulse in the pulsed light group is converted.

Pulsed electromagnetic-wave generator and measuring apparatus

An optical response measuring device is provided with a light source, first and second wavelength conversion elements and a light intensity sensor array. The light source generates a pair of light beams including light beams of first and second wavelengths, and the first wavelength conversion element generates measurement light. The measurement light is irradiated on an object for measurement and a detection light having first phase and second phase is obtained in response to this irradiation. A reference light that carries the phase of the pair of the pair light beams and the detection light both pass through a second wavelength conversion element to obtain a modulated reference light have first and second intensities. The first and second local intensities are then measured by the light intensity sensor array.

Optical response measuring device and optical response measuring method

The present invention includes a slanted periodically poled deviceincluding a light input surfaceand a light output surfaceparallel to each other and a terahertz wave input surfaceorthogonal to the light input surfaceand the light output surface, a pump beam sourcewhich emits pump beamperpendicularly to the light input surface, and a photodetectorwhich detects an up-conversion signal beam A converted from a terahertz waveemitted perpendicularly from the light output surface. The slanted periodically poled deviceis configured to generate the up-conversion signal beam A in the same direction as and in parallel with the pump beamby quasi phase matching between the terahertz waveperpendicularly incident from the terahertz wave input surfaceand the pump beam

Terahertz wave detection device and method

Growing community of inventors

Saitama, Japan

Kouji Nawata