Riken Corporation

Ken-ichiro Maki

Chiko Otani

Kodo Kawase

Takayuki Shibuya

First and second laser beams are incident on a difference frequency mixing unit, and the two laser beams overlap in the difference frequency mixing unit, thereby generating a terahertz wave whose frequency is a frequency difference between the two laser beams. Each laser beam has a spatial spread in a frequency gradient direction, and a spatial frequency distribution of each laser beam is a distribution in which a magnitude of a frequency gradually increases in the frequency gradient direction. A frequency difference between the two laser beams is equal in each position in an overlapping region of the two laser beams. A terahertz wave of a single frequency is generated from this overlapping region. By spatially shifting the first laser beam and the second laser beam with respect to each other in the frequency gradient direction, the frequency difference in the overlapping region is changed, which changes the single frequency.

Terahertz wave generating method and apparatus

To provide a terahertz beam scanning apparatus and method that can scan a terahertz beam at high speed over a wide angle. The terahertz beam scanning apparatus includes: a laser devicethat generates a first laser beamand a second laser beamhaving different wavelengths; a laser optical systemthat focuses the first laser beamand the second laser beamon a same common focal point; and a terahertz generatorthat is located at the common focal point and generates a terahertz beamby difference frequency mixing. The laser optical systemis configured to be capable of changing a relative incidence &#x3b8;between the first laser beam and the second laser beam to the terahertz generator.

Growing community of inventors

Saitama, Japan

Ken-ichiro Maki