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Speckle reduction in laser imaging applications using rotating magneto-optical disk

Chien-Sheng Liu, Yu-Ching Chang, Kun-Wei Lin, Po-Heng Lin
Effective methods for speckle reduction are essential in improving the image quality of laser imaging applications. Accordingly, the present study proposes a novel technique for reducing the speckle contrast in laser imaging applications by means of the magneto-optic Kerr effect induced by a ... [J. Opt. Soc. Am. A 31, 16-20 (2014)]

Development of a YAG laser system for the edge Thomson scattering system in ITER

T. Hatae, E. Yatsuka, T. Hayashi, H. Yoshida, T. Ono et al.
A prototype YAG laser system for the edge Thomson scattering system in ITER has been newly developed. Performance of the laser amplifier was improved by using flow tubes made of samarium-doped glass; the small signal gain reached 20 at its maximum. As a result, an output energy of 7.66 J at 100 Hz w ... [Rev. Sci. Instrum. 83, 10E344 (2012)] published Wed Aug 15, 2012.

Controlled near-field enhanced electron acceleration from dielectric nanospheres with intense few-cycle laser fields

Controlled near-field enhanced electron acceleration from dielectric nanospheres with intense few-cycle laser fields

Nature Physics 7, 656 (2011).
doi:10.1038/nphys1983

Authors: Sergey Zherebtsov, Thomas Fennel, Jürgen Plenge, Egill Antonsson, Irina Znakovskaya, Adrian Wirth, Oliver Herrwerth, Frederik Süßmann, Christian Peltz, Izhar Ahmad, Sergei A. Trushin, Vladimir Pervak, Stefan Karsch, Marc J. J. Vrakking, Burkhard Langer, Christina Graf, Mark I. Stockman, Ferenc Krausz, Eckart Rühl & Matthias F. Kling

A detailed study through the focal region of near-threshold single-shot femtosecond laser ablation nano-holes in borosilicate glass

Publication year: 2011
Source: Optics Communications, In Press, Uncorrected Proof, Available online 7 September 2011
B., Delobelle , R., Salut , F., Courvoisier , P., Delobelle
A detailed study of the morphology of nano-craters drilled in borosilicate glass by single shot femtosecond laser ablation near the ablation threshold has been performed by scanning electron microscopy, atomic force microscopy and scanning electron microscopy imaging after focused ion beam sectioning. The influence of the numerical aperture (NA=0.4 and 0.8), the pulse energy (16nJ

BOR-FDTD analysis of nonlinear Fiber Bragg grating and distributed Bragg resonator

Publication year: 2011
Source: Optics & Laser Technology, In Press, Corrected Proof, Available online 4 March 2011
Mohamed B., EL_Mashade , M., Nady
Recently, nonlinear materials have attracted a great deal of attention because of their importance in designing new devices to meet a need range of optical systems. An intense investigation of the possibility of using these materials for all optical ultrafast applications is achieved by allowing their dielectric characteristics to be varied in such a way that a periodic perturbation of their refractive index along the length of the waveguide will be formed. The Finite-Difference Time-Domain (FDTD) method, on the other hand, has been proven to be one of the most powerful numerical techniques that are usefully applied to a wide...

Photoacoustic absorption spectrometer for highly transparent dielectrics with parts-per-million sensitivity

Niklas Waasem, Stephan Fieberg, Janosch Hauser, Gregory Gomes, Daniel Haertle et al.
A sensitive photoacoustic absorption spectrometer for highly transparent solids has been built and tested. As the light source an optical parametrical oscillator pumped by a nanosecond pulse laser with 10 Hz repetition rate is employed, covering the complete wavelength range from 407 to 2600 nm. A s ... [Rev. Sci. Instrum. 84, 023109 (2013)] published Tue Feb 26, 2013.

High-efficiency diode-pumped actively Q-switched ceramic Nd:YAG/BaWO_4 Raman laser operating at 1666  nm

H. N. Zhang, X. H. Chen, Q. P. Wang, X. Y. Zhang, J. Chang, L. Gao, H. B. Shen, Z. H. Cong, Z. J. Liu, X. T. Tao, P. Li
A diode-pumped actively Q-switched Raman laser employing BaWO_4 as the Raman active medium and a ceramic Nd:YAG laser operating at 1444 nm as the pump source is demonstrated. The first-Stokes–Raman generation at 1666 nm is achieved. With a pump power of 20.3 W and pulse ... [Opt. Lett. 39, 2649-2651 (2014)]

Uniformity of the lasing wavelength of heterogeneously integrated InP microdisk lasers on SOI

P. Mechet, F. Raineri, A. Bazin, Y. Halioua, T. Spuesens, T. J. Karle, P. Regreny, P. Monnier, D. Van Thourhout, I. Sagnes, R. Raj, G. Roelkens, G. Morthier
We report a high lasing wavelength uniformity of optically pumped InP-based microdisk lasers processed with electron-beam lithography, heterogeneously integrated with adhesive bonding on silicon-on-insulator (SOI) waveguide circuits and evanescently coupled to an underlying waveguide. We study the ... [Opt. Express 21, 10622-10631 (2013)]

Suppression of pointing instability in quantum cascade lasers by transverse mode control

Pierre M. Bouzi, Peter Q. Liu, Nyan Aung, Xiaojun Wang, Jen-Yu Fan et al.
We report on a technique that serves to eliminate pointing instability in Quantum Cascade lasers by suppressing the propagation of higher order transverse modes within the laser cavity. This process, achieved via a short and lossy lateral constriction in the waveguide, only allows the fundamental mo ... [Appl. Phys. Lett. 102, 122105 (2013)] published Tue Mar 26, 2013.

1.3-ns pulse, compact passively Q-switched microchip green laser by Nd:YAG/Cr4+:YAG composite crystal

Abstract  
In this article, a diode-end-pumped passively Q-switched extra-cavity frequency doubled micro-type green laser by Nd:YAG/Cr4+:YAG composite crystal was demonstrated. The dependence of the average out power, pulse width and pulse repetition rate on
incident pump power were measured. Under the pump power of 14 W, the minimum pulse width of 1.3 ns with repetition rate of
68.0 kHz was obtained, corresponding single-pulse energy of 8.8 μJ and peak power of 6.7 kW.

Stimulated Raman scattering spectroscopy and χ(3)-nonlinear lasing effects in single crystals of aragonite (orthorhombic CaCO3)

Abstract

The present work gives a brief review of the nonlinear χ(2)- and χ(3)-lasing properties of SRS-active natural crystals (minerals) known so far. This compilation complements new results of a detailed investigation of Raman induced χ(3)-effects in aragonite single crystals (orthorhombic CaCO3) under single- and dual-wavelength picosecond excitation in the UV, visible and near-IR spectral ranges. The studied effects at room and cryogenic temperatures comprise Stokes and anti-Stokes combs of almost two octaves bandwidth, THG, SFG, as well as cascaded and cross-cascaded χ(3)χ(3) interactions.

Static and dynamic characteristics of integrated semiconductor optical parametric oscillators

Nima Zareian, Amr S. Helmy
The static and dynamic properties of semiconductor optical parametric oscillators (SOPOs) are studied by merging the rate equations of the diode pump laser with those of the OPO while taking into account the phase and, hence, chirp performance. The static analysis of the SOPO shows two stable ... [J. Opt. Soc. Am. B 30, 2306-2317 (2013)]

Cytomorphological changes in buccal mucosa of patients treated with low-level 1,064-nm laser radiation

Abstract  
The aim of this study was to examine the cytomorphological changes occurring in the buccal mucosa in patients treated with
low-level 1,064-nm laser radiation. Seventeen individuals (12 males, five females) 18–24 years of age were included in the
study. Low-level 1,064-nm laser radiation was applied to the right buccal mucosa near the premolar region; this therapy was
repeated for 10 days. Buccal epithelial cells were collected from the right and left premolar regions of the individuals with
a brush before and after therapy. The specimens collected from the left side were measured cytomorphometrically and used for
the control group. Student’s t test was used for statistical comparison of the values of the buccal epithelial cells collected from individuals; a p value < 0.05 was considered statistically significant. None of the patients showed any adverse reactions to the low-level
1,064-nm laser radiation therapy during application.

Effect of processing kinetics on the structure of ferromagnetic-ferroelectric-ferromagnetic interfaces

P. S. Sankara Rama Krishnan, Q. M. Ramasse, Wen-I Liang, Ying-Hao Chu, V. Nagarajan et al.
Trilayer heterostructures consisting of a ferroelectric bismuth ferrite (BFO) film sandwiched between ferromagnetic lanthanum strontium manganese oxide (LSMO) films were fabricated using pulsed laser deposition. Both BFO thicknesses (20 nm, 5 nm) and cooling rates were varied to investigate the role ... [J. Appl. Phys. 112, 104102 (2012)] published Wed Nov 21, 2012.

Terahertz inverse synthetic aperture radar imaging using self-mixing interferometry with a quantum cascade laser

H. S. Lui, T. Taimre, K. Bertling, Y. L. Lim, P. Dean, S. P. Khanna, M. Lachab, A. Valavanis, D. Indjin, E. H. Linfield, A. G. Davies, A. D. Rakić
We propose a terahertz (THz)-frequency synthetic aperture radar imaging technique based on self-mixing (SM) interferometry, using a quantum cascade laser. A signal processing method is employed which extracts and exploits the radar-related information contained in the SM signals, enabling the ... [Opt. Lett. 39, 2629-2632 (2014)]

High signal-to-noise ratio, single-frequency 2  μm Brillouin fiber laser

Yongfeng Luo, Yulong Tang, Jianlong Yang, Yao Wang, Shiwei Wang, Kunyu Tao, Li Zhan, Jianqiu Xu
A high optical signal-to-noise ratio (OSNR) single-frequency 2 μm Brillouin fiber laser (BFL) with watt-level output and high transfer efficiency is demonstrated for the first time to the best of our knowledge. The Brillouin pump is constructed with a two-stage thulium-doped fiber ... [Opt. Lett. 39, 2626-2628 (2014)]

Temporal dynamics of spatially localized waves in quadratic nonlinear waveguide arrays

Author(s): Frank Setzpfandt, Alexander S. Solntsev, Dragomir N. Neshev, Thomas Pertsch, Wolfgang Sohler, and Roland Schiek

We study experimentally and theoretically the temporal dynamics of laser pulses propagating under conditions of spatial self-focusing in quadratic nonlinear waveguide arrays made from periodically poled lithium niobate. We observed temporal pulse breakup and temporal pulse narrowing and studied the ...

[Phys. Rev. A 89, 033863] Published Mon Mar 31, 2014

Nonlinear optical and thermal properties of BCP: PMMA films determined by thermal self-diffraction

Publication date:
30 December 2013
Source:Optics & Laser Technology, Volume 54
Author(s): Alaa Y. AL-Ahmad , Mohammed F. AL-Mudhaffer , Hussain A. Badran , Chassib A. Emshary

Generation of regular femtosecond pulses in AlGaInP semiconductor laser

Publication year: 2011
Source: Optics Communications, In Press, Uncorrected Proof, Available online 5 March 2011
Vladimir, Lebedev , Yauhen, Katsiashou , Viktoryia, Makarevich
It is shown experimentally that stable ~200fs regular pulses and optical frequency comb spectrum containing ~70 discrete frequencies can be achieved using semiconductor injection laser working in the conditions of superfluorescence under dc pumping current, which is lower than the threshold of laser action.
 Research highlights: ►Femtosecond pulse generation from a 650nm AlGaInP laser. ►The pump current is below the threshold of continuous laser action. ►Field autocorrelation shows a stable 200fs pulse train with 12ps spacing. ►The spectrum is a frequency comb with 70 peaks under bell-shaped envelope.

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