公开(公告)号：US20200183251A1

公开(公告)日：2020-06-11

申请号：US16637774

申请日：2018-07-30

Applicant: TOPCON CORPORATION ,  RIKEN

Inventor： Yoshikiyo MORIGUCHI ,  Hiroaki MINAMIDE

IPC: G02F2/00 ,  G02F1/35 ,  G02F1/39 ,  H01S3/10

Abstract: 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.

公开(公告)号：US20200166822A1

公开(公告)日：2020-05-28

申请号：US16338134

申请日：2017-09-26

Applicant: RIKEN

Inventor： Kouji NAWATA ,  Yu TOKIZANE ,  Hiroaki MINAMIDE

IPC: G02F1/39 ,  G02F1/37 ,  H01S3/108

Abstract: 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 Λ. When the pump light enters the nonlinear optical element, idler light LI and signal light LTHz 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′p obtained by vector addition or subtraction of a grating vector kΛ which corresponds to the inversion period, to or from a pump light wave vector kp 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.

公开(公告)号：US20170307515A1

公开(公告)日：2017-10-26

申请号：US15517925

申请日：2015-10-05

Applicant: RIKEN

Inventor： Kouji NAWATA ,  Hiroaki MINAMIDE ,  Shuzhen FAN ,  Feng QI ,  Hiromasa ITO

IPC: G01N21/17 ,  G02F1/365 ,  G02F1/37 ,  G01N21/3581 ,  G02F1/35

CPC classification number: G01N21/17 ,  G01N21/3581 ,  G02F1/365 ,  G02F1/37 ,  G02F2001/354

Abstract: 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. The first wavelength conversion element generates measurement light of a wavelength whose phase is maintained with relative to the pair of light beams incident thereon. The measurement light is irradiated to an object for measurement. The detected light is then made incident on the second wavelength conversion element. Reference light carries the phase of the pair of light beams and light for which the phase is to be determined in the detection light, from which the second wavelength conversion element generates modulated reference light. The modulated reference light is modulated to have first and second local intensities, which are then measured by the light intensity sensor array.

公开(公告)号：US20140299773A1

公开(公告)日：2014-10-09

申请号：US14249046

申请日：2014-04-09

Applicant: RIKEN

Inventor： Kouji NAWATA ,  Hiroaki MINAMIDE ,  Hiromasa ITO ,  Shin'ichiro HAYASHI

IPC: G01J1/04 ,  G01J1/42 ,  G02F1/365

CPC classification number: G01J1/0425 ,  G01J1/42 ,  G01J3/0205 ,  G01J3/18 ,  G01J3/42 ,  G01N21/3581 ,  G02F1/3558 ,  G02F1/365 ,  G02F2001/3548 ,  G02F2203/13

Abstract: The present invention includes a slanted periodically poled device 12 including a light input surface 12a and a light output surface 12b parallel to each other and a terahertz wave input surface 12c orthogonal to the light input surface 12a and the light output surface 12b, a pump beam source 14 which emits pump beam 1 perpendicularly to the light input surface 12a, and a photodetector 16 which detects an up-conversion signal beam A converted from a terahertz wave 3 emitted perpendicularly from the light output surface 12b. The slanted periodically poled device 12 is configured to generate the up-conversion signal beam A in the same direction as and in parallel with the pump beam 1 by quasi phase matching between the terahertz wave 3 perpendicularly incident from the terahertz wave input surface 12c and the pump beam 1.

Abstract translation: 本发明包括一个倾斜的周期极化装置12，它包括彼此平行的光输入表面12a和光输出表面12b以及与光输入表面12a和光输出表面12b正交的太赫波输入表面12c， 源极14，其垂直于光输入表面12a发射泵浦光束1;以及光电检测器16，其检测从从光输出表面12b垂直发射的太赫兹波3转换的上转换信号光束A. 倾斜的周期性极化装置12被配置为通过从太赫兹波输入表面12c垂直入射的太赫兹波3和从太赫兹波输入表面12c的太赫兹波3之间的准相位匹配，在与泵浦光束1相同的方向上产生上变换信号光束A， 泵梁1。