We demonstrate a scalable approach to addressing multiple atomic qubits for use in quantum information processing. Individually trapped 87 Rb atoms in a linear array are selectively manipulated with a single laser guided by a microelectromechanical beam steering system. Single qubit oscillations are shown on multiple sites at frequencies of Ӎ3.5 MHz with negligible crosstalk to neighboring sites. Switching times between the central atom and its closest neighbor were measured to be 6 -7 s while moving between the central atom and an atom two trap sites away took 10-14 s.

Abstract:We present a beam steering system based on microelectromechanical systems technology that features high speed steering of multiple laser beams over a broad wavelength range. By utilizing high speed micromirrors with a broadband metallic coating, our system has the flexibility to simultaneously incorporate a wide range of wavelengths and multiple beams. We demonstrate reconfiguration of two independent beams at different wavelengths (780 and 635 nm) across a common 5×5 array with 4 µs settling time. Full simulation of the optical system provides insights on the scalability of the system. Such a system can provide a versatile tool for applications where fast laser multiplexing is necessary. References and links

High-efficiency collection of photons emitted by a point source over a wide field of view (FoV) is crucial for many applications. Multiscale optics offer improved light collection by utilizing small optical components placed close to the optical source, while maintaining a wide FoV provided by conventional imaging optics. In this work, we demonstrate collection efficiency of 26% of photons emitted by a pointlike source using a micromirror fabricated in silicon with no significant decrease in collection efficiency over a 10 mm object space. © 2010 Optical Society of America OCIS codes: 270.5585, 120.4820.Efficient collection of photons emitted by a point source requires an optical system with high numerical aperture (NA). It is difficult to design an optical system featuring a high NA over a wide field of view (FoV) using costeffective conventional refractive optical elements. Lens systems with NA ¼ 0:85 and a FoV of over 25 mm have been realized for lithography applications [1]. However, such optical systems utilize a large number of lens elements and suffer from optical loss, complexity, size, weight, and cost. In conventional applications, the NA of the collection optics is limited to about 0.5, corresponding to a 7% collection efficiency of photons emitted from a point source. The use of reflective and diffractive optics, like curved mirrors and Fresnel lenses [2], opens up the possibility of dramatically enhancing the photon collection efficiency. Recent experiments and proposals using trapped ions demonstrate the benefit of reflective optical elements for imaging [3], state detection, and ionphoton coupling applications [4,5]. While these approaches can dramatically increase the photon collection efficiency, macroscopic reflectors suffer from large geometric aberrations, which need to be corrected in order to distinguish light from multiple point sources. In this work, we employ a multiscale optical design [6] to increase the photon collection efficiency from a single point source, which can be extended to high-efficiency collection from an array of point sources. This design uses a single conventional objective lens and places a high NA micromirror behind each point source to allow for high-efficiency collection. The ability to image the point sources in a continuous FoV is sacrificed in exchange for high-efficiency collection from each point source in a discontinuous FoV. This way, dramatic improvements are possible in integration time and data acquisition speed for applications where image resolution is determined by the light excitation source and not by the collection optics, including determination of the internal state of a single atom [7][8][9], confocal laser scanning microscopy [10], and confocal Raman microspectroscopy [11]. The collection efficiency from each point source is determined by the high NA of the micromirror, while the number of point-source-micromirror combinations that can be measured simultaneously is determined by the FoV of the macroscopic imaging system. In our system design ( F...

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In order to provide scalability to quantum information processors utilizing trapped atoms or ions as quantum bits (qubits), the capability to address multiple individual qubits in a largeSome of the most promising physical implementations of quantum information processors (QIPs) utilize internal states of ions coupled via Coulomb interactions [1][2][3][4] or neutral atoms coupled through dipole-dipole interactions [5,6] to represent quantum bits (qubits). Manipulation of qubit states in these QIP implementations require precisely controlled laser beams. While architectures for scalable QIPs have been proposed, [7] their realization is limited by available technology. [8] To improve the scalability of these experiments, an effective means of delivering laser beams to multiple qubit locations is required. Requirements such as fast addressing times (∼ 1µs) imposed by qubit dephasing, [9] broad range of operational wavelengths (UV for trapped ions [2][3][4] and IR for neutral atoms [9,10]), and scalable addressing of thousands of locations exclude the possibility of using traditional optical components. Acousto-optical modulators have been used to provide beam steering to several qubit locations [11], but this approach introduces a frequency shift and is difficult and costly to scale. Optical micro-electromechanical systems (MEMS) can provide a variety of optical 1