Virtual Journal of Laser is a web tool to help laser researchers follow new publications from major academic journals, discover and promote interesting works by voting, commenting and simply visiting. Subscribe Virtual Journal of Laser to take the advantage! Read more...
If you find VJLaser helpful, please consider donation for covering the host costage. Many thanks!
Publication year: 2010
Source: Optics & Laser Technology, In Press, Corrected Proof, Available online 15 May 2010
Sudden changes in reflectivity within a small angle or wavelength range are very sensitive to both the metal film thickness and optical constants. Metal films such as silver or gold display two sudden changes in their reflectance curve − the first occurring at the critical angle, which is then followed by a sharp surface plasmon resonance (SPR) dip at an incident angle that is a few degrees greater than the critical angle. In this report, we describe a method involving the optimization of the sum of squared difference (SSQ) to produce good fitting amongst the reflectivity data points from a...
Publication year: 2010
Source: Optics & Laser Technology, In Press, Corrected Proof, Available online 14 May 2010
Iman A., Mahdy , E.P., Domashevskaya , P.V., Seredin , O.B., Yatsenko
Optical spectral features of CoxGeyTe100−x−y amorphous thin films where 10≤x≤35 and 41≤y≤47 were studied for the first time. The transmittance and reflectance at normal incidence have been measured at room temperature in the spectral range 190–2500nm. Refractive index and extinction coefficient have been evaluated in the above spectral range. Band tail width and energy gap were strongly affected by cobalt concentration in the “as prepared” amorphous thin film. Absorption band spectrum on the basis of the imaginary parts of the dielectric constant, ε2, ε1, refractive index, and extinction coefficient are also affected by cobalt content. On the other hand, the...
Source:Optics & Laser Technology, Volume 60
Author(s): Ayan Ray , Md. Sabir Ali , Alok Chakrabarti
S. Hubert, J. L. Dubois, D. Gontier, G. Lidove, C. Reverdin et al.
The laser integration line (LIL) located at CEA-CESTA is equipped with x-ray plasma diagnostics using different kinds of x-ray components such as filters, mirrors, crystals, detectors, and cameras. The CEA-DAM of Arpajon is currently developing x-ray calibration methods and carrying out absolute cal ... [Rev. Sci. Instrum. 81, 053501 (2010)] published Thu May 13, 2010.
Author(s): Morten Bache and Frank W. Wise
The output pulses of a commercial high-power femtosecond fiber laser or amplifier are typically around 300–500 fs with wavelengths of approximately 1030 nm and tens of microjoules of pulse energy. Here, we present a numerical study of cascaded quadratic soliton compression of such pulses in LiNbO_...
[Phys. Rev. A 81, 053815] Published Tue May 11, 2010
Chun-Chieh Liao, Kuo-Yu Wu, Yu-Hung Lien, Horst Knöckel, Hsiang-Chen Chui, Eberhard Tiemann, Jow-Tsong Shy
High precision frequency measurements of I127_2 hyperfine transitions in the wavelength range between 750 and 780 nm were performed employing an optical frequency comb. A Ti:sapphire laser is frequency stabilized to a hyperfine component of I_2 using a Doppler-free frequency modulation technique, ... [J. Opt. Soc. Am. B 27, 1208-1214 (2010)]
Reported here is the first cryogenically-cooled performance of Er3+-doped Y2O3 laser based on 4I11/2 [rarr] 4I13/2 transitions. Laser material was diode-pumped directly into an upper laser manifold 4I11/2 in order to minimize quantum defect of this Mid-IR laser. CW output power of over 1.6 W at [sim]2.7 Î¼m was achieved with the 27.5% slope efficiency, which is approaching the quantum defect-limited efficiency value despite the marginal optical quality of the available laser sample. (© 2010 by Astro Ltd., Published exclusively by WILEY-VCH Verlag GmbH & Co. KGaA)
The aim of this study is to show that SR-FTIRM can be successfully applied for the detection of early apoptotic processes in the human glioma cells (U-87 MG). The apoptosis was induced by photodynamic action after irradiation of either photosensitizer hypericin (Hyp) or a complex of Hyp with low-density lipoproteins (Hyp/LDL) incorporated into the cells. The differences between infrared (IR) spectra of non-treated and photodynamically treated U-87 MG cells are mainly manifested in position of Amide I vibrational band, sensitive to changes in protein secondary structure. The conformational transition [alpha] -helix to [beta] -sheet results in the shift of Amide I vibration to lower frequency, and can be explained as a consequence of the processes leading to apoptosis. It is also shown that the sensitivity of SR-FTIRM for the detection of early apoptotic signs is comparable, or even higher, than that of classic technique usually used for the detection of early apoptosis, flow-cytometry study of cell staining by Annexin V.
Strong-field physics: Unexpected gain
Nature Physics 6, 406 (2010). doi:10.1038/nphys1692
Author: Lukas Gallmann
A newly identified physical process in the interaction of strong laser fields with matter paves the way for broadband amplification of light in the extreme ultraviolet to soft-X-ray spectral region.
Toshiyuki Shizuma, Takehito Hayakawa, Ryoichi Hajima, Nobuhiro Kikuzawa, Hideaki Ohgaki et al.
Nondestructive identification of heavy isotopes concealed in a thick iron box has been demonstrated by using nuclear resonance fluorescence. A quasi-monochromatic photon beam produced by the collision of laser quanta with high energy electrons was used for resonant excitation of nuclear levels in Pb ... [Rev. Sci. Instrum. 83, 015103 (2012)] published Thu Jan 5, 2012.
Minsong Wei, Fei Xing, Zheng You
Stringent attitude determination accuracy through a high bandwidth is required for the development of the advanced space technologies, such as earth observation and laser communication. In this work, we presented a novel proposal for a digital sun sensor with high accuracy, large Field of View ... [Opt. Express 21, 32524-32533 (2013)]
An erbium-doped polycrystalline yttrium aluminum garnet (
Publication year: 2010
Source: Optics Communications, In Press, Uncorrected Proof, Available online 24 September 2010
Chenghou, Tu , Zhangchao, Huang , Shuanggen, Zhang , Minglie, Hu , Qingyue, Wang , ...
The frequency doubling of femtosecond pulses from an Yb-doped fiber laser source was demonstrated in a PPKTP waveguide fabricated by femtosecond laser direct writing. The PPKTP waveguide contains a fixed period of 8.9μm and the feomtosecond fundamental pulses have a central wavelength of 1044nm. A maximum SHG power of 406mW was produced, yielding a conversion efficiency of 5.6%. Numerical simulations were carried out to investigate the property of frequency doubling for femtosecond pulses. The results show that the SHG process proceeds even the quasi-phase-matching (QPM) condition is not well satisfied, which is significantly different from that of “long” pulses or...
Nonlinear dynamics: Chaotic billiard lasers
Nature 465, 696 (2010). doi:10.1038/465696a
Authors: A. Douglas Stone
The chaotic motion of light rays gives microlasers surprising emission properties, enhancing quantum tunnelling by many orders of magnitude and producing highly directional output beams.
Publication year: 2010
Source: Optics & Laser Technology, In Press, Corrected Proof, Available online 11 June 2010
H., Arellano-Sotelo , A.V., Kir’yanov , Yu.O., Barmenkov , V., Aboites
We report the use of nonlinear dynamics of an erbium-doped fiber laser (EDFL) at pump modulation, namely the period-1 pulsed regime, for intra-cavity loss sensing and demonstrate noticeable sensitivity enhancement of an EDFL-based sensor, provided by this arrangement. Experimentally, we obtain a ten-fold increase of the sensor response, i.e. peak-to-peak pulse amplitude against loss variation, as compared with the standard sensing schemes using a low-power wide-spectrum light emitting diode (LED) or fiber laser without external modulation. This advantage originates from a strong dependence of pulse amplitude in the period-1 regime on intra-cavity loss variable that is, in turn, determined by...