2,042 research outputs found
A quasi-monomode guided atom-laser from an all-optical Bose-Einstein condensate
We report the achievement of an optically guided and quasi-monomode atom
laser, in all spin projection states ( -1, 0 and ) of F=1 in
Rubidium 87. The atom laser source is a Bose-Einstein condensate (BEC) in a
crossed dipole trap, purified to any one spin projection state by a
spin-distillation process applied during the evaporation to BEC. The atom laser
is outcoupled by an inhomogenous magnetic field, applied along the waveguide
axis. The mean excitation number in the transverse modes is for and for the low field seeker
All-optical 160 Gbit/s RZ data retiming system incorporating a pulse shaping fibre Bragg grating
We characterize a 160Gbit/s retimer based on flat-topped pulses shaped using a superstructured fibre Bragg grating. The benefits of using shaped rather than conventional pulse forms in terms of timing jitter reduction are confirmed by bit-error-rate measurements
A detector for continuous measurement of ultra-cold atoms in real time
We present the first detector capable of recording high-bandwidth real time
atom number density measurements of a Bose Einstein condensate. Based on a
two-color Mach-Zehnder interferometer, our detector has a response time that is
six orders of magnitude faster than current detectors based on CCD cameras
while still operating at the shot-noise limit. With this minimally destructive
system it may be possible to implement feedback to stabilize a Bose-Einstein
condensate or an atom laser.Comment: 3 pages, 3 figures, submitted to optics letter
Pulsed pumping of a Bose-Einstein condensate
In this work, we examine a system for coherent transfer of atoms into a
Bose-Einstein condensate. We utilize two spatially separate Bose-Einstein
condensates in different hyperfine ground states held in the same dc magnetic
trap. By means of a pulsed transfer of atoms, we are able to show a clear
resonance in the timing of the transfer, both in temperature and number, from
which we draw conclusions about the underlying physical process. The results
are discussed in the context of the recently demonstrated pumped atom laser.Comment: 5 pages, 5 figures, published in Physical Review
Achieving peak brightness in an atom laser
In this paper we present experimental results and theory on the first
continuous (long pulse) Raman atom laser. The brightness that can be achieved
with this system is three orders of magnitude greater than has been previously
demonstrated in any other continuously outcoupled atom laser. In addition, the
energy linewidth of a continuous atom laser can be made arbitrarily narrow
compared to the mean field energy of a trapped condensate. We analyze the flux
and brightness of the atom laser with an analytic model that shows excellent
agreement with experiment with no adjustable parameters.Comment: 4 pages, 4 black and white figures, submitted to Physical Revie
A multibeam atom laser: coherent atom beam splitting from a single far detuned laser
We report the experimental realisation of a multibeam atom laser. A single
continuous atom laser is outcoupled from a Bose-Einstein condensate (BEC) via
an optical Raman transition. The atom laser is subsequently split into up to
five atomic beams with slightly different momenta, resulting in multiple,
nearly co-propagating, coherent beams which could be of use in interferometric
experiments. The splitting process itself is a novel realization of Bragg
diffraction, driven by each of the optical Raman laser beams independently.
This presents a significantly simpler implementation of an atomic beam
splitter, one of the main elements of coherent atom optics
An FPGA-based controller for collaborative robotics
The use of robots is becoming more common in society. Industrial robots are being developed to work with people, and lower-force collaborative robots are being developed to help people in their everyday lives. These may need fast and sophisticated motion control and behavioral algorithms, but are expected to be more compact and lower cost. This paper proposes a processor plus FPGA solution for the control systems for such robots, where the FPGA performs all real-time tasks, freeing the processor to run lower-frequency high level control and interface to other devices such as camera systems. A demonstrator robot is designed, combining multi-axis motion control with 3D robot vision
Optical waveform sampling of a 320 Gbits/s serial data signal using a hydrogenated amorphous silicon waveguide
We propose using a hydrogenated amorphous silicon waveguide for ultra-high-speed serial data waveform sampling. 320 Gbit/s serial optical data sampling is experimentally demonstrated with +12 dB intrinsic four wave mixing conversion efficiency
All-optical wavelength conversion and multichannel 2R regeneration based on highly nonlinear dispersion-imbalanced loop mirror
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