836 research outputs found
Diamond chemical vapor deposition on optical fibers for fluorescence waveguiding
A technique has been developed for depositing diamond crystals on the
endfaces of optical fibers and capturing the fluorescence generated by
optically active defects in the diamond into the fiber. This letter details the
diamond growth on optical fibers and transmission of fluorescence through the
fiber from the nitrogen-vacancy (N-V) color center in diamond. Control of the
concentration of defects incorporated during the chemical vapor deposition
(CVD) growth process is also demonstrated. These are the first critical steps
in developing a fiber coupled single photon source based on optically active
defect centers in diamond.Comment: 10 pages, 3 figure
Quantum gate for Q switching in monolithic photonic bandgap cavities containing two-level atoms
Photonic bandgap cavities are prime solid-state systems to investigate
light-matter interactions in the strong coupling regime. However, as the cavity
is defined by the geometry of the periodic dielectric pattern, cavity control
in a monolithic structure can be problematic. Thus, either the state coherence
is limited by the read-out channel, or in a high Q cavity, it is nearly
decoupled from the external world, making measurement of the state extremely
challenging. We present here a method for ameliorating these difficulties by
using a coupled cavity arrangement, where one cavity acts as a switch for the
other cavity, tuned by control of the atomic transition.Comment: 6 pages, 5 figures, 1 tabl
Imaging and quantum efficiency measurement of chromium emitters in diamond
We present direct imaging of the emission pattern of individual
chromium-based single photon emitters in diamond and measure their quantum
efficiency. By imaging the excited state transition dipole intensity
distribution in the back focal plane of high numerical aperture objective, we
determined that the emission dipole is oriented nearly orthogonal to the
diamond-air interface. Employing ion implantation techniques, the emitters were
engineered with various proximities from the diamond-air interface. By
comparing the decay rates from the single chromium emitters at different depths
in the diamond crystal, an average quantum efficiency of 28% was measured.Comment: 11 pages and 4 figure
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Reply on the comment on the paper "Superconducting transition in Nb nanowires fabricated using focused ion beam"
In this communication we present our response to the recent comment of A.
Engel regarding our paper on FIB- fabricated Nb nanowires (see Vol. 20 (2009)
Pag. 465302). After further analysis and additional experimental evidence, we
conclude that our interpretation of the experimental results in light of QPS
theory is still valid when compared with the alternative proximity-based model
as proposed by A. Engel.Comment: 3 pages, 1 figure, accepted by Nanotechnolog
Optical and electronic properties of sub-surface conducting layers in diamond created by MeV B-implantation at elevated temperatures
Boron implantation with in-situ dynamic annealing is used to produce highly
conductive sub-surface layers in type IIa (100) diamond plates for the search
of a superconducting phase transition. Here we demonstrate that high-fluence
MeV ion-implantation, at elevated temperatures avoids graphitization and can be
used to achieve doping densities of 6 at.%. In order to quantify the diamond
crystal damage associated with implantation Raman spectroscopy was performed,
demonstrating high temperature annealing recovers the lattice. Additionally,
low-temperature electronic transport measurements show evidence of charge
carrier densities close to the metal-insulator-transition. After electronic
characterization, secondary ion mass spectrometry was performed to map out the
ion profile of the implanted plates. The analysis shows close agreement with
the simulated ion-profile assuming scaling factors that take into account an
average change in diamond density due to device fabrication. Finally, the data
show that boron diffusion is negligible during the high temperature annealing
process.Comment: 22 pages, 6 figures, submitted to JA
Coupling of nitrogen-vacancy centers in diamond to a GaP waveguide
The optical coupling of guided modes in a GaP waveguide to nitrogen-vacancy
(NV) centers in diamond is demonstrated. The electric field penetration into
diamond and the loss of the guided mode are measured. The results indicate that
the GaP-diamond system could be useful for realizing coupled microcavity-NV
devices for quantum information processing in diamond.Comment: 4 pages 4 figure
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