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

Abstract

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.

Single quantum dot spectroscopy using a fiber taper waveguide near-field optic

“…7 Other researchers have proposed 8,9 and realized their use as a collection tool for spontaneous emission from atomic vapors. 10 Here, we show that a fiber taper may be used to channel emission from single selfassembled QDs embedded in a semiconductor slab directly into a standard single-mode fiber with high efficiency ͑ϳ0.1% ͒, and to provide submicron spatial resolution of QDs.The QDs we study consist of a single layer of InAs QDs embedded in an In 0.15 Ga 0.85 As quantum well, a so-called dotin-a-well ͑DWELL͒ structure. 11 The DWELL layer is grown in the center of a GaAs waveguide ͑total waveguide thickness of 256 nm͒, which sits atop a 1.5 m thick Al 0.7 Ga 0.3 As buffer layer.…”

“…7 Other researchers have proposed 8,9 and realized their use as a collection tool for spontaneous emission from atomic vapors. 10 Here, we show that a fiber taper may be used to channel emission from single selfassembled QDs embedded in a semiconductor slab directly into a standard single-mode fiber with high efficiency ͑ϳ0.1% ͒, and to provide submicron spatial resolution of QDs.…”

Rate-equation approach to cavity-mediated laser cooling

“…Instead of expanding the Hamiltonian H I in Eq. (17) in η, we solve the cooling equations for small Lamb-Dicke parameters η perturbatively. The reason that our calculations are nevertheless relatively straightforward is that we replace the phonon and the cavity-photon annihilation operators b and c in the interaction Hamiltonian H I by two new bosonic operators x and y [cf.…”

“…Systematic experimental studies of cavity-mediated laser cooling have subsequently been reported by Rempe and co-workers [3][4][5][6], Vuletić and co-workers [7][8][9][10], and others [11,12]. Recent atom-cavity experiments access an even wider range of experimental parameters by replacing conventional high-finesse cavities [13,14] with optical ring cavities [15,16] and tapered nanofibers [17,18] and by combining optical cavities with atom-chip technology [19,20], atomic conveyer belts [21,22], and ion traps [23]. Moreover, Wickenbrock et al [24] recently reported the observation of collective effects in the interaction of cold atoms with a lossy optical cavity.…”

A linear atomic quantum coupler

“…Moreover, the coupling of atomic dipoles to the evanescent field of tapered optical fibers has been demonstrated in [25,26]. In this respect the optical nanofibers can manipulate and probe singleatom fluorescence.…”