公开(公告)号：US11800629B2

公开(公告)日：2023-10-24

申请号：US16799626

申请日：2020-02-24

Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION ,  RIKEN

Inventor： Hiromitsu Imai ,  Tomoyo Akatsuka ,  Katsuya Oguri ,  Atsushi Ishizawa ,  Hideki Gotoh ,  Hidetoshi Katori ,  Masao Takamoto

IPC: H05H3/02 ,  G21K1/093 ,  G04F5/14

CPC classification number: H05H3/02 ,  G04F5/145 ,  G21K1/093

Abstract: A magneto-optical trap apparatus includes a vacuum vessel for encapsulating an atom to be trapped, an anti-Helmholtz coil for applying a magnetic field to an inside of the vacuum vessel, a laser device for generating a laser beam, and an irradiation device for irradiating the generated laser beam from a plurality of directions. The laser beam includes a first laser beam detuned from a first resonance frequency when the atom transits from a total angular momentum quantum number F in a ground state to a total angular momentum quantum number F′=F+1 in an excited state, and a second laser beam detuned from a second resonance frequency when the atom transits from the total angular momentum quantum number F in the ground state to a total angular momentum quantum number F′=F−1 in the excited state, among transitions from J=0 in a ground state to J′=1 in an excited state.

公开(公告)号：US12035456B2

公开(公告)日：2024-07-09

申请号：US18461176

申请日：2023-09-05

Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION ,  RIKEN

Inventor： Hiromitsu Imai ,  Tomoya Akatsuka ,  Katsuya Oguri ,  Atsushi Ishizawa ,  Hideki Gotoh ,  Hidetoshi Katori ,  Masao Takamoto

IPC: H05H3/02 ,  G04F5/14 ,  G21K1/093

CPC classification number: H05H3/02 ,  G04F5/145 ,  G21K1/093

Abstract: A magneto-optical trap method including applying a magnetic field to an atom encapsulated in a vacuum vessel and having a nuclear spin of not less than 3/2 by using an anti-Helmholtz coil. Then generating a laser beam including a first laser beam detuned from a first resonance frequency when the atom transits from a total angular momentum quantum number F in a ground state to a total angular momentum quantum number F′=F+1 in an excited state, and a second laser beam detuned from a second resonance frequency when the atom transits from the total angular momentum quantum number F in the ground state to a total angular momentum quantum number F′=F−1 in the excited state.

公开(公告)号：US20240027870A1

公开(公告)日：2024-01-25

申请号：US18245430

申请日：2020-10-01

Applicant: Nippon Telegraph and Telephone Corporation

Inventor： Yuya Yonezu ,  Atsushi Ishizawa ,  Hidetaka Nishi ,  Tai Tsuchizawa ,  Nobuyuki Matsuda ,  Rai Takahashi ,  Koji Yamada

IPC: G02F1/35 ,  G01N21/41 ,  G02F1/365

CPC classification number: G02F1/3526 ,  G01N21/41 ,  G02F1/365

Abstract: An optical nonlinearity measurement method according to the present disclosure utilizes photon pair generation through a spontaneous four-wave mixing process, to observe photon pairs using an optical waveguide loaded with a two-dimensional material. Compared with the Z-scan method, the influence of free carriers on nonlinear refractive indexes is only indirect. With a parameter being the length of the attached two-dimensional material in the optical waveguide direction, a theoretical value of the coincidence rate of the photon pairs based on the coupled wave equation is fitted to a measured value of the coincidence rate of the photon pairs. For the coincidence rate of the photon pairs, the theoretical value based on the coupled wave equation is fitted to the measured value in a state reflecting the structure of the optical waveguide loaded with the two-dimensional material, and nonlinear coefficients γ1 and γ2 at that time are obtained.