272 research outputs found
Decomposition of NO studied by infrared emission and CO laser absorption
A diagnostic technique for monitoring the concentration of NO using absorption of CO laser radiation was developed and applied in a study of the decomposition kinetics of NO. Simultaneous measurements of infrared emission by NO at 5.3 microns were also made to validate the laser absorption technique. The data were obtained behind incident shocks in NO-N2O-Ar (or Kr) mixtures, with temperatures in the range 2400-4100 K. Rate constants for dominant reactions were inferred from comparisons with computer simulations of the reactive flow
Characterizing photonic crystal waveguides with an expanded k-space evanescent coupling technique
We demonstrate a direct, single measurement technique for
characterizing the dispersion of a photonic crystal waveguide (PCWG)
using a tapered fiber evanescent coupling method. A highly curved fiber
taper is used to probe the Fabry-Pérot spectrum of a closed PCWG over a
broad k-space range, and from this measurement the dispersive properties of
the waveguide can be found. Waveguide propagation losses can also be
estimated from measurements of closed waveguides with different lengths.
The validity of this method is demonstrated by comparing the results
obtained on a ‘W1’ PCWG in chalcogenide glass with numerical
simulation
Enhanced spontaneous emission rate from single InAs quantum dots in a photonic crystal nanocavity at telecom wavelengths
The authors demonstrate coupling at 1.3 micro m between single InAs quantum dots (QDs) and a mode of a two dimensional photonic crystal (PhC) defect cavity with a quality factor of 15 000. By spectrally tuning the cavity mode, they induce coupling with excitonic lines. They perform a time integrated and time-resolved photoluminescence and measure an eightfold increase in the spontaneous emission rate inducing a coupling efficiency of 96%. These measurements indicate the potential of single QDs in PhC cavities as efficient single-photon emitters for fiber-based quantum information processing applications. [on SciFinder (R)
A case of the amniotic constrictions in a newborn child (Simonart syndrome)
We want to present a case of the amniotic constrictions in a newborn child. Today there are no ethiopathogenetic treatment methods for treating complications of amniotic constrictions. All available treatment methods are symptomatic and are mainly aimed at patient care. In rare cases, surgical correction of the defect is possible, sometimes even in the intrauterine period. The peculiarity of this case is late, postnatal detection of multiple malformations in a newborn child with timely observation of a pregnant woman in the women’s consultation
Integrated liquid-core optical fibers --- ultra-efficient nonlinear liquid photonics
We have developed a novel integrated platform for liquid photonics based on
liquid core optical fiber (LCOF). The platform is created by fusion splicing
liquid core optical fiber to standard single-mode optical fiber making it fully
integrated and practical - a major challenge that has greatly hindered progress
in liquid-photonic applications. As an example, we report here the realization
of ultralow threshold Raman generation using an integrated CS2 filled LCOF
pumped with sub-nanosecond pulses at 1064nm and 532nm. The measured energy
threshold for the Stokes generation is ~ 1nJ, about three orders of magnitude
lower than previously reported values in the literature for hydrogen gas. The
integrated LCOF platform opens up new possibilities for ultralow power
nonlinear optics such as efficient white light generation for displays, mid-IR
generation, slow light generation, parametric amplification, all-optical
switching and wavelength conversion using liquids that have orders of magnitude
larger optical nonlinearities compared with silica glass.Comment: 4 pages, 3 figure
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