A step forward to miniaturizing “optical lattice clocks” －A technique allowing high-precision portable-clocks will open up clocks’ new applications in the future－： Professor Hidetoshi Katori, Department of Applied Physics.
Research group of Professor Hidetoshi Katori, Department of Applied Physics, the University of Tokyo has succeeded in high-precision spectroscopy of strontium atoms trapped inside a hollow-core photonic crystal fiber. This is an important achievement toward miniaturization of quantum devices.
Currently, optical lattice clocks have been extensively studied all over the world as a leading candidate for the future "redefinition of the second." For their practical use, miniaturized portable clocks are pursued. The research group confined laser-cooled strontium atoms inside a hollow-core fiber, and has succeeded in high-precision spectroscopy. By trapping atoms in an optical lattice tuned to the magic condition inside the hollow-core fiber, the researchers prevent atoms from colliding each other and with fiber walls, without causing frequency shift due to the lattice confinement. Consequently, they observed natural-linewidth-limited atomic spectrum inside the fiber. Their experiments demonstrate that use of a hollow-core fiber allows to increase the optical density of atoms while reducing atomic interactions. The technique will find broad applications in miniaturizing platforms for quantum metrology, including optical lattice clocks.