. (2013) A surface-patterned chip as a strong source of ultracold atoms for quantum technologies. Nature Nanotechnology, 8 (5). pp. 321-324. Copyright © 2013 MacMillanA copy can be downloaded for personal non-commercial research or study, without prior permission or chargeThe content must not be changed in any way or reproduced in any format or medium without the formal permission of the copyright holder(s) Laser cooled atoms are central to modern precision measurements 1-6 . They are also increasingly important as an enabling technology for experimental cavity quantum electrodynamics 7,8 , quantum information processing 9-11 and matter wave interferometry 12 . Although significant progress has been made in miniaturising atomic metrological devices 13,14 , these are limited in accuracy by their use of hot atomic ensembles and buffer gases. Advances have also been made in producing portable apparatus that benefit from the advantages of atoms in the microKelvin regime 15,16 . However, simplifying atomic cooling and loading using microfabrication technology has proved difficult 17,18 . In this letter we address this problem, realising an atom chip that enables the integration of laser cooling and trapping into a compact apparatus. Our source delivers ten thousand times more atoms than previous magneto-optical traps with microfabricated optics and, for the first time, at sub-Doppler temperatures. Moreover, the same chip design offers a simple way to form stable optical lattices. These features, combined with the simplicity of fabrication and the ease of operation, make these new traps a key advance in the development of cold-atom technology for high-accuracy, portable measurement devices.

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We demonstrate ultrafast, high throughput, all-optical switching in optimized, 2-cm-long, halfand full-beat-length nonlinear directional couplers operated at 1.55 pm, below half the band gap of Ga, s2Ala1sAs. The long device length allowed the elimination of nonlinear loss and resulted in a switching peak power and energy of 85 W and 65 pJ, respectively.

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Received8August 1994, in final form and acceptedforpublication27February1995 Absiract. Resuits are presented which demonstraie ine existence of unambiguous three-dimensional quantum confinement of phonons within crystallites of the Il-VI semiconductor CdSe, which were prepared by t h e method of diffusive growth within a doped glassmatrix.Theconfinement was investigated by meansof Ramanscattering from zone centre longitudinal optical (LO) phonons. These Raman spectra illustrate LO phonon peaks showing a low-energy shifl and broadening with decreasing crystallite size. The experimental measurements are compared with a theoretical model of phonon confinement which includes a size distribution parameter. The experimental results are in good agreement with the predictions of this model. Surface vibrational modes and the effects of hydrostatic pressure from t h e glass matrix do not appear to be of significance i n the samples investigated.