Fedja Oručević

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We study cold collisions between trapped ions and trapped atoms in the semiclassical (Langevin) regime. Using Yb+ ions confined in a Paul trap and Yb atoms in a magneto-optical trap, we investigate charge-exchange collisions of several isotopes over three decades of collision energies down to 3 mueV (k_{B}x35 mK). The minimum measured rate coefficient of(More)
We report on a novel single-photon source using a single calcium ion trapped between the end facets of two optical fibers. The optical fibers act as photonic channels, and in addition their metallic jackets provide a trapping electric field for the ion. Our system successfully combines a stable single-atom emitter with fiber optics, demonstrating remarkable(More)
We report the direct observation of the electromagnetic-field distribution of whispering gallery modes in silica microcavities (spheres and toroids). It is revealed by their excitation efficiency with a tapered fiber coupler swept along the meridian. The originality of this method lies in the use of the coupler itself for the near-field mapping, eliminating(More)
We have produced high transmission sub-wavelength tapered optical fibers for the purpose of whispering gallery mode coupling in fused silica microcavities at 780 nm. A detailed analysis of the fiber transmittance evolution during tapering is demonstrated to reflect precisely the mode coupling and cutoff in the fiber. This allows to control the final size,(More)
A quantum memory [1,2,3], i.e. a device for storing and retrieving quantum states, is a key element of any quantum information processor. Optical memory access is highly desirable, since it is intrinsically fast, and single photons are robust, easily controlled carriers of quantum states. While a bit of quantum information (qubit) can be stored in a single(More)
We present a novel method of machining optical fiber surfaces with a CO₂ laser for use in Fiber-based Fabry-Perot Cavities (FFPCs). Previously FFPCs were prone to large birefringence and limited to relatively short cavity lengths (≤ 200 μm). These characteristics hinder their use in some applications such as cavity quantum electrodynamics with trapped ions.(More)
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