4,259 research outputs found
Spontaneous two photon emission from a single quantum dot
Spontaneous two photon emission from a solid-state single quantum emitter is
observed. We investigated photoluminescence from the neutral biexciton in a
single semiconductor quantum dot coupled with a high Q photonic crystal
nanocavity. When the cavity is resonant to the half energy of the biexciton,
the strong vacuum field in the cavity inspires the biexciton to simultaneously
emit two photons into the mode, resulting in clear emission enhancement of the
mode. Meanwhile, suppression was observed of other single photon emission from
the biexciton, as the two photon emission process becomes faster than the
others at the resonance.Comment: 13 pages, 4 figure
A web server for interactive and zoomable Chaos Game Representation images
Chaos Game Representation (CGR) is a generalized scale-independent Markov transition table, which is useful for the visualization and comparative study of genomic signature, or for the study of characteristic sequence motifs. However, in order to fully utilize the scale-independent properties of CGR, it should be accessible through scale-independent user interface instead of static images. Here we describe a web server and Perl library for generating zoomable CGR images utilizing Google Maps API, which is also easily searchable for specific motifs. The web server is freely accessible at , and the Perl library as well as the source code is distributed with the G-language Genome Analysis Environment under GNU General Public License
Ultralow mode-volume photonic crystal nanobeam cavities for high efficiency coupling to individual carbon nanotube emitters
We report on high efficency coupling of individual air-suspended carbon
nanotubes to silicon photonic crystal nanobeam cavities. Photoluminescence
images of dielectric- and air-mode cavities reflect their distinctly different
mode profiles and show that fields in the air are important for coupling. We
find that the air-mode cavities couple more efficiently, and estimated
spontaneous emission coupling factors reach a value as high as 0.85. Our
results demonstrate advantages of ultralow mode-volumes in air-mode cavities
for coupling to low-dimensional nanoscale emitters.Comment: 4 pages, 4 figure
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