7,067 research outputs found
Generation of frequency multiplexed entangled single photons assisted by the entanglement
We present a scheme to generate the frequency multiplexed entangled (FME)
single photons based on the entanglement between two species atomic mixture
ensemble. The write and reads fields driven according to a certain timing
sequence, the generation of FME single photons can be repeated until success is
achieved. The source might have significant applications in wavelength division
multiplexing quantum key distribution.Comment: 4 pages, 4 figures, submitted to PR
Modulating light with light via giant nano-opto-mechanical nonlinearity of plasmonic metamaterial
From the demonstration of saturable absorption by Vavilow and Levshin in
1926, and with invention of the laser, unavailability of strongly nonlinear
materials was a key obstacle for developing optical signal processing, in
particular in transparent telecommunication networks. Today, most advanced
photonic switching materials exploit gain dynamics and near-band and excitonic
effects in semiconductors, nonlinearities in organic media with
weakly-localized electrons and nonlinearities enhanced by hybridization with
metamaterials. Here we report on a new type of artificial nonlinearity that is
nano-opto-mechanical in nature. It was observed in an artificial metamaterial
array of plasmonic meta-molecules supported by a flexible nano-membrane. Here
nonlinearity is underpinned by the reversible reconfiguration of its structure
induced by light. In a film of only 100 nanometres thickness we demonstrated
modulation of light with light using milliwatt power telecom diode lasers.Comment: 6 pages, 5 figure
Alimentary canal of the lesser house fly, Fannia canicularis (Linnaeus) (Diptera: Fanniidae)
The alimentary canal of Fannia canicularis was studied intensively for the first time, highlighting the description of morphological characteristics and providing detailed morphometric data. Two pairs of Malpighian tubules with considerably different length were found which has been rarely documented for Calyptratae flies before. Furthermore, stout cardia and sinewy crop of the samples were ob- served and supposed to be responsible for the energy needed to support the long- time swarming behavior of the species
Retrieval of phase memory in two independent atomic ensembles by Raman process
In spontaneous Raman process in atomic cell at high gain, both the Stokes
field and the accompanying collective atomic excitation (atomic spin wave) are
coherent. We find that, due to the spontaneous nature of the process, the
phases of the Stokes field and the atomic spin wave change randomly from one
realization to another but are anti-correlated. The phases of the atomic
ensembles are read out via another Raman process at a later time, thus
realizing phase memory in atoms. The observation of phase correlation between
the Stokes field and the collective atomic excitations is an important step
towards macroscopic EPR-type entanglement of continuous variables between light
and atoms
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