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Related papers: Optothermal nonlinearity of silica aerogel

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Optical coatings formed from amorphous oxide thin films have many applications in precision measurements. The Advanced Laser Interferometer Gravitational-Wave Observatory (LIGO) and Advanced Virgo use coatings of SiO$_2$ (silica) and…

Materials Science · Physics 2021-04-29 Elenna M. Capote , Amy Gleckl , Jazlyn Guerrero , Michael Rezac , Robert Wright , Joshua R. Smith

Collisional absorption of laser light in a homogeneous, under-dense plasma is studied by a new particle-in-cell (PIC) simulation code considering one-dimensional slab-plasma geometry. Coulomb collisions between charge particles in plasma…

Plasma Physics · Physics 2017-03-06 M. Kundu

Hybrid lead halide perovskites, such as CH$_3$NH$_3$PbX$_3$ (X=I, Br), are direct gap semiconductors that offer many superior optoelectronic properties combined with extremely simple solution-processing fabrication methods. This makes them…

Photoluminescence is observed at room temperature from phonon-assisted band-to-band emission in Si (1.067 eV peak) using unpatterned bulk p-type silicon wafer samples that were spin-coated with Er-doped (6 at. %) silica-gel films (0.13…

Materials Science · Physics 2012-02-06 Sufian Abedrabbo , Bashar Lahlouh , Sudhakar Shet , Anthony Fiory

We directly measure the nonlinear optical response in argon and nitrogen in a thin gas target to laser intensities near the ionization threshold. No instantaneous negative nonlinear refractive index is observed, nor is saturation, in…

Optics · Physics 2015-05-28 J. K. Wahlstrand , Y. -H. Cheng , Y. -H. Chen , H. M. Milchberg

We discuss recent measurements of the wavelength-dependent absorption coefficients in deep South Pole ice. The method uses transit time distributions of pulses from a variable-frequency laser sent between emitters and receivers embedded in…

Optics · Physics 2009-10-30 L. Bergstrom

Tin oxide aerogels were synthesized using an epoxide-assisted technique and characterized with Fourier transform infrared, X-ray diffraction, and UV-Vis to study the effects of post-synthesis annealing and peroxide treatment. While bulk tin…

Materials Science · Physics 2024-10-02 John F. Hardy , Madison King , Stephanie Hurst , Carlo R. daCunha

We discover two infrared objects that show deep absorption features of H2O, CO2, and CO ices in the AKARI/Infrared Camera (IRC) slit-less spectroscopic survey of the Galactic plane in 2.5--13 micron. Both objects are located neither in…

Astrophysics of Galaxies · Physics 2021-08-11 Takashi Onaka , Tomoyuki Kimura , Itsuki Sakon , Takashi Shimonishi

We present multi-sightline absorption spectroscopy of cool gas around three lensing galaxies at z=0.4-0.7. These lenses have half-light radii r_e=2.6-8 kpc and stellar masses of log M*/Ms=10.9-11.4, and therefore resemble nearby passive…

Astrophysics of Galaxies · Physics 2016-03-23 Fakhri S. Zahedy , Hsiao-Wen Chen , Michael Rauch , Michelle L. Wilson , Ann Zabludoff

Optical conductivity (OC) can serve as a measure of correlation effects in a wide range of condensed matter systems. We here show that the long-range tail of the Coulomb interaction yields a universal correction to the OC in a…

Mesoscale and Nanoscale Physics · Physics 2017-10-18 Bitan Roy , Vladimir Juricic

A search for the near-infrared water-ice absorption band was made in a number of very red OH/IR stars which are known to exhibit the 10um silicate absorption. As a by-product, accurate positions of these highly reddened objects are…

Astrophysics · Physics 2009-11-11 K. Justtanont , G. Olofsson , C. Dijkstra , A. W. Meyer

In hydrogenated amorphous silicon oxide (a-SiO:H) films, incorporation of oxygen enhances optical gap due to a large number of St-O-Si bond formation, which lies deep into valence band states. An induction effect of this Si-O on other bonds…

Condensed Matter · Physics 2007-11-17 S. M. Iftiquar

The multiple passages of light through an absorption inhomogeneity of finite size deep within a turbid medium is analyzed for optical imaging using the ``self-energy'' diagram. The nonlinear correction becomes more important for an…

Soft Condensed Matter · Physics 2009-11-10 M. Xu , W. Cai , R. R. Alfano

A generic novel model governing optical pulse propagation in a nonlinear dispersive amplifying medium with asymmetric (linear spectral slope) gain is introduced. We examine the properties of asymmetric optical pulses formed in such…

The study uses AACVD technology with nitrogen carrier gas to make AZO thin films through which it determines structural, optical, and morphological changes from 0 to 20 percent aluminum doping. The depositions took place at 400 degrees…

In this paper, the interaction of a 1064 nm continuum-wave laser with inductively-coupled plasma generated in a fluorescent light bulb has been studied both experimentally and theoretically. The absorption coefficients pertaining to the…

Plasma Physics · Physics 2020-02-17 M. Fatih Yilmaz , M. Elif Tanriseven , Edgar Obonyo , Y. Danisman

We study the column densities of neutral atomic, molecular, and warm ionized Galactic gas through their continuous absorption of extragalactic X-ray spectra at |b| > 25 degrees. For N(H,21cm) < 5x10^20 cm^-2 there is an extremely tight…

Astrophysics · Physics 2014-10-13 John S. Arabadjis , Joel N. Bregman

Thanks to their unique properties, nematic liquid crystals feature a variety of mechanisms for light-matter interactions. For continuous-wave optical excitations, the two dominant contributions stem from reorientational and thermal…

Chandra high-resolution spectra toward eight low-mass Galactic binaries have been analyzed with a photoionization model that is capable of determining the physical state of the interstellar medium. Particular attention is given to the…

Instrumentation and Methods for Astrophysics · Physics 2015-06-19 E. Gatuzz , J. García , C. Mendoza , T. R. Kallman , M. A. Bautista , T. W. Gorczyca

It has been suggested that anisotropic quasiparticle scattering will stabilize anisotropic phases of superfluid $^3$He contained within highly porous silica aerogel. For example, global anisotropy introduced via uniaxial compression of…

Superconductivity · Physics 2009-04-24 J. P. Davis , J. Pollanen , B. Reddy , K. R. Shirer , H. Choi , W. P. Halperin