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Ultrafast lasers are becoming more common
in biophotonics and medical applications as
well as for Terahertz generation and material
processing. Hands-off reliable operation and
highest performance are major requirements
for these lasers.
pulses and highest powers – offering
(488 – 2200 nm)
PicoFYb (1030/1064 nm)
FemtoFErb (1560 nm)
(488 – 640 nm tunable)
A Passion for Precision.
Electroluminescence spectra of two devices at ;8-V bias. Device A (black) shows only emission
due to color centers in the oxide electrodes. Device B (red) clearly shows the peak due to quantum
dot excitonic emission at the expected wavelength. Courtesy of Edward M. Likovich.
single layer of them. They were able to
apply new chemical treatments to it, moving forward.
The research was published online in
Advanced Materials (doi: 10.1002/adma.
Through Harvard’s Office of Technol-
ogy Development, the team has applied
for a provisional patent on the device. The
next step will be to work toward optimiz-
ing its light-emitting efficiency. The re-
searchers are interested in exploring other
features of their ALD-QD composite. For
example, the ALD oxide could protect the
QD during postdeposition chemical treat-
ments that otherwise would cause the
quantum dots to agglomerate and lose
their valuable quantum properties.
Light from vacuum supports quantum principle
GOTHENBURG, Sweden – The quantum
mechanical principle that says a vacuum is
not empty space but full of particles that
fluctuate in and out of existence, has been
observed for the first time as photons were
coaxed to leave this virtual state and be
captured as measurable light.
The 40-year-old principle, known as the
dynamical Casimir effect (DCE), states
that if virtual photons are allowed to
bounce off a mirror moving at near light
speeds, they will become real photons.
Scientists at Chalmers University of Technology have achieved this effect – with
some modifications to the method. Instead
of varying the physical distance to a mirror, the scientists altered the electrical distance to an electrical short circuit that acts
as a mirror for microwaves.
The “mirror” consists of a quantum
electronic component called a Squid
(superconducting quantum interference
device), which is extremely sensitive
to magnetic fields. By changing the
direction of the magnetic field several billions of times a second, the scientists
made the mirror vibrate at a speed of up
to 25 percent of the speed of light. By
transferring some of its kinetic energy to
the virtual photons, the mirror helps them
This resulted in the photons appearing
as pairs within the vacuum, and the pairs
were measured in the form of microwave
radiation. The scientists were able to establish that the radiation had the same
properties quantum theory predicts for
photons that appear in pairs in this way.