We consider mid-infrared (5 - 25 μm), optically cooled detectors based on a microcantilever sensor of the radiation
pressure. The significant enhancement of sensitivity is due the combination of low effective temperature (10 K), non-absorption
detection and a high quality optical microcavity. Spectrometry applications are analyzed. It is shown that an
optically cooled radiation pressure sensor potentially has an order of magnitude better sensitivity than the best
conventional uncooled detectors.
We consider theoretically and numerically the suppression of fluctuations (scintillations) of a laser
beam propagating through turbulent atmospheres by applying a phase modulator. Both spatial and
temporal phase variations introduced by this phase modulator are analyzed. The explicit
dependences of the scintillation index on the initial correlation length and finite-time phase
variations for long propagation paths are obtained. Results of modeling and numerical simulations
are presented. We demonstrate that an appropriately chosen phase modulator can significantly
suppress the scintillations of the laser beam caused by turbulent atmospheres.
Recently we proposed a new approach which potentially has single spin sensitivity, sub-nanometer
spatial resolution, and ability to operate at room temperature (J. Appl. Phys. 97, 014903 (2005);
U.S. Patent No. 7,305,869, 2007). In our approach a nanoscale photoluminescent center exhibits
optically detected magnetic resonance (ODMR) in the vicinity of magnetic moment in the sample
related with unpaired individual electron or nuclear spins, or ensemble of spins. We consider as a
sensor material that exhibit ODMR properties nitrogen-vacancy (N-V) centers in diamond. N-V
centers in diamond has serious advantage having extraordinary chemical and photostability, very
long spin lifetimes, and ability single-spin detection at room temperature. The variety of possible
scanning schemes has been considered. The potential application to 3D imaging of biological
structure has been analyzed.
A new concept of a free-space, high-speed optical communication (FSOC) system based on spectral encoding of radiation
from a broadband pulsed laser is developed. It is known that the intensity fluctuations of a partially coherent beam in
combination with a time-averaging photodetector leads to a significant scintillation reduction with the corresponding
improvement of the bit error rate by several orders of magnitude. Unfortunately, the time-averaging method cannot be
applied directly to gigabit data rate communication. The main limitation of this method is related to the requirement that the
correlation time between different spatially coherent spots be shorter than the response time of the photodetector. We
propose to extend the technique of scintillation suppression, based on time averaging of a partially coherent beam, to gigabit
data rate FSOC. In our approach, information is encoded in the form of amplitude modulation of the spectral components of
the laser pulse which has a broad spectrum. To examine the intensity fluctuations of a partially coherent beam under the
conditions of strong turbulence, we developed an asymptotic method for solution of the kinetic equation for the photon
distribution function. We show that, for long distances, scintillations and beam wandering can be significantly suppressed.
We consider midinfrared (5 - 25 μm) and terahertz (100 - 1000 μm), room-temperature detectors based on a
microcantilever/micromirror sensor of the radiation pressure. The significant enhancement of sensitivity is due the
combination of non-absorption detection and a high quality optical microcavity. Applications for spectrometry and imaging
are analyzed. It is shown that the radiation pressure sensor potentially has sensitivity at the level of or better than the best
conventional uncooled detectors.
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