Srinivasan, K. & Painter, O. Linear and nonlinear optical spectroscopy of a strongly coupled microdisc-quantum dot system. Nature 450, 862-865

Center for the Physics of Information, California Institute of Technology, Pasadena, California 91125, USA.
Nature (Impact Factor: 41.46). 01/2008; 450(7171):862-5. DOI: 10.1038/nature06274
Source: PubMed


Cavity quantum electrodynamics, the study of coherent quantum interactions between the electromagnetic field and matter inside a resonator, has received attention as both a test bed for ideas in quantum mechanics and a building block for applications in the field of quantum information processing. The canonical experimental system studied in the optical domain is a single alkali atom coupled to a high-finesse Fabry-Perot cavity. Progress made in this system has recently been complemented by research involving trapped ions, chip-based microtoroid cavities, integrated microcavity-atom-chips, nanocrystalline quantum dots coupled to microsphere cavities, and semiconductor quantum dots embedded in micropillars, photonic crystals and microdisks. The last system has been of particular interest owing to its relative simplicity and scalability. Here we use a fibre taper waveguide to perform direct optical spectroscopy of a system consisting of a quantum dot embedded in a microdisk. In contrast to earlier work with semiconductor systems, which has focused on photoluminescence measurements, we excite the system through the photonic (light) channel rather than the excitonic (matter) channel. Strong coupling, the regime of coherent quantum interactions, is demonstrated through observation of vacuum Rabi splitting in the transmitted and reflected signals from the cavity. The fibre coupling method also allows us to examine the system's steady-state nonlinear properties, where we see a saturation of the cavity-quantum dot response for less than one intracavity photon. The excitation of the cavity-quantum dot system through a fibre optic waveguide is central to applications such as high-efficiency single photon sources, and to more fundamental studies of the quantum character of the system.

Full-text preview

Available from:
  • Source
    • "In the remainder of this paper, we study the transmission spectra as a function of the cavity-probe laser detuning ∆ C found through the steady-state solutions of the linearized master equation. Parameters used chosen based on recent cavity QED analyses [28] and experiments [30]. The phase difference between g and h, ϑ, has little effect on the conclusions; it is chosen to be π/4 for simplicity. "
    [Show abstract] [Hide abstract]
    ABSTRACT: We describe an approach to optical non-reciprocity that exploits the local helicity of evanescent electric fields in axisymmetric resonators. By interfacing an optical cavity to helicity-sensitive transitions, such as Zeeman levels in a quantum dot, light transmission through a waveguide becomes direction-dependent when the state degeneracy is lifted. Using a linearized quantum master equation, we analyze the configurations that exhibit non-reciprocity, and we show that reasonable parameters from existing cavity QED experiments are sufficient to demonstrate a coherent non-reciprocal optical isolator operating at the level of a single photon.
    Preview · Article · Apr 2014 · Optics Express
  • Source
    • "QD photonic switches based on four kinds of cavity structures: (a) micro-discs, (b) vertical cavities, (c) photonic-crystal waveguides, (d) metallic nanowires. (a) Reproduced with permission from [39], Copyright 2007 Nature. (b) Reproduced with permission from [40], Copyright 2011 American Institute of Physics. "
    [Show abstract] [Hide abstract]
    ABSTRACT: Focusing and guiding light into semiconductor nano-structures can deliver revolutionary concepts for photonic devices, which offer a practical pathway towards next-generation power-efficient optical networks. In this review, we consider the prospects for photonic switches using semiconductor quantum dots (QDs) and photonic cavities which possess unique properties based on their low dimensionality. The optical nonlinearity of such photonic switches is theoretically analysed by introducing the concept of a field enhancement factor. This approach reveals a drastic improvement in both power-density and speed, which is able to overcome the limitations that have beset conventional photonic switches for decades. In addition, the overall power consumption is reduced due to the atom-like nature of QDs, as well as the nano-scale footprint of photonic cavities. Based on this theoretical perspective, the current state-of-the-art QD/cavity switches are reviewed in terms of various optical nonlinearity phenomena that have been utilized to demonstrate photonic switching. Emerging techniques, enabled by cavity nonlinear effects such as wavelength tuning, Purcell-factor tuning and plasmonic effects, are also discussed.
    Full-text · Article · Apr 2014 · Journal of Physics D Applied Physics
  • Source
    • "Microcavity geometries can provide both radiative rate enhancement and high extraction efficiency, and have been a dominant approach to QD single photon sources. While photonic crystal microcavities can be designed for efficient vertical emission with a desired far-field pattern [27], and microdisk cavities can be effectively out-coupled through FTWs [28], the brightest QD microcavity single photon sources to date have been demonstrated using micropillar geometries. A collection efficiency η = 38 % into the first lens was demonstrated in ref. [12], though after all additional optical losses in the collection path, the photon delivery efficiency η del is < 26 % ‡. "
    [Show abstract] [Hide abstract]
    ABSTRACT: We demonstrate a spectrally broadband and effcient technique for collecting photoluminescence from a single InAs quantum dot directly into a standard single mode optical fiber. In this approach, an optical fiber taper waveguide is placed in contact with a suspended GaAs nanophotonic waveguide with embedded quantum dots, forming an effcient and broadband directional coupler with standard optical fiber input and output. Effcient photoluminescence collection over a wavelength range of tens of nanometers is demonstrated, and a maximum collection effciency of 6.05 % (corresponding single photon rate of 3.0 MHz) into a single mode optical fiber was estimated for a single quantum dot exciton.
    Full-text · Article · Apr 2011 · Applied Physics Letters
Show more