Optical Nanofibers

Abstract

The development of optical nanofibers (ONF) and the study and control of their optical properties when coupling atoms to their electromagnetic modes has opened new possibilities for their use in quantum optics and quantum information science. These ONFs offer tight optical mode confinement (less than the wavelength of light) and diffraction-free propagation. The small cross section of the transverse field allows probing of linear and non-linear spectroscopic features of atoms with exquisitely low power. The cooperativity -the figure of merit in many quantum optics and quantum information systems -tends to be large even for a single atom in the mode of an ONF, as it is proportional to the ratio of the atomic cross section to the electromagnetic mode cross section. ONFs offer a natural bus for information and for inter-atomic coupling through the tightly-confined modes, which opens the possibility of one-dimensional many-body physics and interesting quantum interconnection applications. The presence of the ONF modifies the vacuum field, affecting the spontaneous emission rates of atoms in its vicinity. The high gradients in the radial intensity naturally provide the potential for trapping atoms around the ONF, allowing the creation of onedimensional arrays of atoms. The same radial gradient in the transverse direction of the field is responsible for the existence of a large longitudinal component that introduces the possibility of spin-orbit coupling of the light and the atom, enabling the exploration of chiral quantum optics.

Colloquium : Quantum matter built from nanoscopic lattices of atoms and photons

“…The ratio is evaluated both as a function of distance to the fiber (left panel), which clearly shows the evanescent decay of the field away from the fiber surface, and as a function of fiber radius (right panel), which exhibits a maximum when the field confinement A eff is optimized. Beyond these proof-of-principle interfaces of atoms and nanofibers, some experiments have proceeded recently to implement basic quantum coherent phenomena, such as slow light and coherent photon storage (Gouraud et al, 2015;Sayrin, Clausen et al, 2015;Solano et al, 2017).…”

Non-Markovian Collective Emission from Macroscopically Separated Emitters

“…An important figure of merit of the system is its cooperativity C ≡ γ in /γ 3D [47], such that γ in = lim t→∞ ∞ 0 dω |c a (ω, t)| 2 + |c b (ω, t)| 2 is the fraction of the field emitted into the waveguide and γ 3D = γ(1 − β) is the fraction of the field that escapes out to the nonguided modes [48]. In terms of the total emission into the waveguide for the super and subradiant states this parameter takes the form [45] Csup…”

Strongly Correlated Photon Transport in Waveguide Quantum Electrodynamics with Weakly Coupled Emitters

“…In quantum dot systems the emission can be close to unidirectional and β ∼ 1 [28,[63][64][65], however it is difficult to tune several QDs into resonance. On the other hand, hundreds of atoms can be trapped in the evanescent field of a nanofibre and exhibit chiral light-matter interaction [27,[39][40][41][42] albeit with β 1. These have a directionality of ∼ 90% and thus couple residually to the backward propagating mode, which has not been taken into account in the analytics here.…”