K. Hakuta

Optical nanofiber as an efficient tool for manipulating and probing atomic fluorescence

We experimentally demonstrate efficient coupling of atomic fluorescence to the guided mode of a subwavelength-diameter silica fiber, an optical nanofiber. We show that fluorescence of a very small number of atoms, around the nanofiber can be readily observed through a single-mode optical fiber. We also show that such a technique enables us to probe the van der Waals interaction between atoms and surface with high precision by observing the fluorescence excitation spectrum through the nanofiber.

Atom trap and waveguide using a two-color evanescent light field around a subwavelength-diameter optical fiber

We suggest using a two-color evanescent light field around a subwavelength-diameter fiber to trap and guide atoms. The optical fiber carries a red-detuned light and a blue-detuned light, with both modes far from resonance. When both input light fields are circularly polarized, a set of trapping minima of the total potential in the transverse plane is formed as a ring around the fiber. This design allows confinement of atoms to a cylindrical shell around the fiber. When one or both of the input light fields are linearly polarized, the total potential has two local minimum points in the transverse plane. This design allows confinement of atoms to two straight lines parallel to the fiber axis. Due to the small thickness of the fiber, we can use far-off-resonance fields with substantially differing evanescent decay lengths to produce a net potential with a large depth, a large coherence time, and a large trap lifetime. For example, a 0.2-\ensuremath{\mu}m-radius silica fiber carrying 30 mW of 1.06-\ensuremath{\mu}m-wavelength light and 29 mW of 700-nm-wavelength light, both fields circularly polarized at the input, gives for cesium atoms a trap depth of 2.9 mK, a coherence time of 32 ms, and a recoil-heating-limited trap lifetime of 541 s.

Atom trapping and guiding with a subwavelength-diameter optical fiber

We suggest using an evanescent wave around a thin fiber to trap atoms. We show that the gradient force of a red-detuned evanescent-wave field in the fundamental mode of a silica fiber can balance the centrifugal force when the fiber diameter is about two times smaller than the wavelength of the light and the component of the angular momentum of the atoms along the fiber axis is in an appropriate range. As an example, the system should be realizable for cesium atoms at a temperature of less than

Efficient channeling of fluorescence photons from single quantum dots into guided modes of optical nanofiber.

0.29\phantom{\rule{0.3em}{0ex}}\mathrm{mK}

Cavity formation on an optical nanofiber using focused ion beam milling technique.

using a silica fiber with a radius of

Single atoms on an optical nanofibre

0.2\phantom{\rule{0.3em}{0ex}}\ensuremath{\mu}\mathrm{m}

Cavity quantum electrodynamics on a nanofiber using a composite photonic crystal cavity.

and a

Cavity-enhanced channeling of emission from an atom into a nanofiber

1.3\text{\ensuremath{-}}\ensuremath{\mu}\mathrm{m}

Photonic crystal formation on optical nanofibers using femtosecond laser ablation technique

-wavelength light with a power of about

Laser‐induced fluorescence spectrum of the CCN radical with an Ar+ laser

27\phantom{\rule{0.3em}{0ex}}\mathrm{mW}