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Dinu LC Muller HG Kazamias S Mullot G Augé F Balcou P Paul PM Kovacev M Breger P Agostini P 《Physical review letters》2003,91(6):063901
The absolute timing of the high-harmonic attosecond pulse train with respect to the generating IR pump cycle has been measured for the first time. The attosecond pulses occur 190+/-20 as after each pump field maxima (twice per optical cycle), in agreement with the "short" quantum path of the quasiclassical model of harmonic generation. 相似文献
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Jean-Ulrich Mullot Sara Karolak Anne Fontova Bruno Huart Yves Levi 《Analytical and bioanalytical chemistry》2009,394(8):2203-2212
Pollution of the environment by pharmaceuticals is a subject of growing scientific and societal concern. However, few quantitative
data have been reported concerning hospital wastewater contamination. Among the different molecules used at hospital, antineoplastic
drugs appear to be of special interest, and 5-fluorouracil (5-FU) can be considered as a key compound of this therapeutic
class. To monitor this pharmaceutical in hospital wastewater, a highly specific and selective method was developed using gas
chromatography tandem mass spectrometry after solid-phase extraction. This sensitive method (limit of quantification = 40 ng L−1) was then applied to assess sewage contamination of a middle-size hospital with oncology service located in Paris, France.
Native 5-FU was detectable in 12 of the 14 analysed samples. In positive samples, concentration range was measured from 0.09
to 4.0 μg L−1. Finally, a predicting model for the hospital wastewater concentrations is presented, and results of this model are discussed. 相似文献
3.
S.?KazamiasEmail author D.?Douillet C.?Valentin Th.?Lefrou G.?Grillon G.?Mullot F.?Augé P.?Mercére Ph.?Zeitoun Ph.?Balcou 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2003,26(1):47-50
Following the theoretical predictions [1], the observation of two-photon processes by interaction of vacuum ultraviolet (VUV) radiation with inner-shell levels of atoms requires focused intensities in the 1013-1014 W/cm2 range. Our aim is to reach this regime in order to study non-linear optics at these wavelengths. We first optimized the high harmonic conversion efficiency in argon by studying the best experimental conditions for phase-matching, concentrating on focus geometry related to laser energy, cell length and position relative to the focus. We then studied the resulting harmonic beam focusability by a toroidal mirror (f=10 cm) and made an image of the harmonic focus. We conclude with an evaluation of the focused intensity that we are able to reach experimentally.Received: 28 January 2003, Published online: 24 April 2003PACS:
32.80.Rm Multiphoton ionization and excitation to highly excited states (e.g., Rydberg states) - 42.65.Ky Frequency conversion; harmonic generation, including higher-order harmonic generation 相似文献
4.
G. L. Bourdet R. A. Muller G. M. Mullot J. Y. Vinet 《Applied physics. B, Lasers and optics》1987,44(2):107-110
In this paper, we report on a new concept for active mode locking of lasers. It has been successfully applied to a cw waveguide CO2 laser and pulse widths as short as 2 ns have been obtained. 相似文献
5.
A molecularly imprinted polymer (MIP) was synthesized and evaluated to selectively extract an alpha-blocker, i.e. alfuzosin, from human plasma. The synthesis of the MIP was performed in dichloromethane with methacrylic acid as monomer and the target drug as template. A first series of experiments was carried out in dichloromethane to estimate the potential of the MIP in its specific recognition medium, i.e. dichloromethane, by developing a selective procedure and by measuring the capacity of the sorbent. An optimized procedure was developed for the selective extraction of alfuzosin with a recovery close to 100% in this medium and a specific capacity of 1.3 micromol g(-1) of MIP was measured. A study in aqueous media was also carried out by a comprehensive approach of the retention mechanism in order to build a selective procedure of extraction. The effects of the amount and of the charge of cations were studied and an optimal pH value was defined to limit matrix effects. Then, the alfuzosin MIP was then directly used to selectively extract the target drug from human plasma with an extraction recovery of 60%. Lastly, a soil was extracted by a pressurized solvent and the resulting extract was cleaned up on the MIP, showing the possibility to use this selective sorbent for the sample treatment of various complex matrices. 相似文献
6.
P. Balcou R. Haroutunian S. Sebban G. Grillon A. Rousse G. Mullot J.-P. Chambaret G. Rey A. Antonetti D. Hulin L. Roos D. Descamps M.B. Gaarde A. L’Huillier E. Constant E. Mevel D. von der Linde A. Orisch A. Tarasevitch U. Teubner D. Klöpfel W. Theobald 《Applied physics. B, Lasers and optics》2002,74(6):509-515
We present a review of some recent results on high-order-harmonic generation, aiming at optimizing the photon flux to allow
for future applications in extreme-ultra-violet non-linear optics. We first present new schemes to control phase matching
of high harmonics in gases, by using the effect of the spatially varying atomic phase displayed by the high harmonics. An
enhancement by a factor of 50 is observed in neon in conditions for which the gradient of the atomic dispersion balances the
electronic dispersion. A new scheme to manipulate the laser field was demonstrated, and shown to improve phase matching. We
then turn to high-harmonic generation by solid targets, and show that high harmonics generated by an intense 30-fs laser pulse
remain collimated even at the threshold of the relativistic regime.
Received: 5 December 2001 / Published online: 24 April 2002 相似文献
7.
We have built a diode-pumped Nd:glass regenerative amplifier that is able to produce energies up to 20 mJ within a 470-fs pulse duration at a 1-Hz repetition rate. We obtained this amplifier by using specific intracavity components such as a phase mirror and a birefringent filter to generate a large spatial mode and a large spectral width. 相似文献
8.
Valentin C Douillet D Kazamias S Lefrou T Grillon G Augé F Mullot G Balcou P Mercère P Zeitoun P 《Optics letters》2003,28(12):1049-1051
We present a direct method of studying the focusability of an intense, short-pulse extreme-ultraviolet (XUV) beam obtained by high-harmonic generation. We perform near-field imaging of the focal spot of five high-harmonic orders strongly focused by a broadband toroidal mirror. To visualize the focal spot directly, we image the fluorescence induced by an XUV beam on a cerium-doped YAG crystal on a visible CCD camera. We can thus measure the harmonic spot size on a single image, together with the Strehl ratio, to evaluate the quality of focusing. Such techniques should become instrumental in optimizing the focusing conditions and reaching intensities required for exploring attosecond nonlinear optics in the XUV range. 相似文献
9.
Reitze DH Kazamias S Weihe F Mullot G Douillet D Augé F Albert O Ramanathan V Chambaret JP Hulin D Balcou P 《Optics letters》2004,29(1):86-88
An adaptive learning loop enhances the efficiency and tuning of high-order harmonic generation. In comparison with simple chirp tuning, we observe a broader tuning range and a twofold to threefold enhancement in integrated photon flux in the cutoff region. The driving pulse temporal phase varies significantly for different tunings and is more complicated than a simple chirp. We compare our experimental results with a one-dimensional, time-dependent model that incorporates the intrinsic atomic response, the experimental pulse temporal phase, ionization effects, and transverse coherence of the spatial mode of the laser. The model agrees with our experimental results and indicates that a specific quantum path coupled with ionization effects determines the optimized harmonic spectrum. 相似文献
10.
G. L. Bourdet R. A. Muller G. M. Mullot J. Y. Vinet 《Applied physics. B, Lasers and optics》1987,43(4):273-279
Injection phase locking of a powerful CO2 waveguide laser with a stable singlefrequency master oscillator is described. The locking range is experimentally investigated versus both injected signal frequency and slave cavity length. A locking tunability up to ±180 MHz from CO2 10P(20) line center has been achieved. Experimental results are in excellent agreement with the theoretical development exposed in the preceeding paper. 相似文献
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