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排序方式: 共有222条查询结果,搜索用时 15 毫秒
11.
N. Huot J.M. Jonathan G. Pauliat P. Georges A. Brun G. Roosen 《Applied physics. B, Lasers and optics》1999,69(2):155-157
Intra-cavity dynamic holography is proposed as a self-adaptive, easy to set up technique for efficient laser mode manipulation.
A first implementation is presented here as a longitudinal mode selector providing a spectacular spectral narrowing in linear
laser cavities operating both in the pulsed and the cw regimes.
Received: 12 April 1999 / Published online: 24 June 1999 相似文献
12.
13.
G. J. Spühler K. J. Weingarten R. Grange L. Krainer M. Haiml V. Liverini M. Golling S. Schön U. Keller 《Applied physics. B, Lasers and optics》2005,81(1):27-32
We present two novel semiconductor saturable absorber mirror (SESAM) designs which can exhibit more than ten times lower saturation
fluence than classical SESAM devices. Design considerations and characterization data are presented. These devices are particularly
suited for passively mode-locked lasers with ultra-high repetition rates. 相似文献
14.
M. E. Fermann 《Applied physics. B, Lasers and optics》1994,58(3):197-209
An overview of ultrashort-pulse sources based on single-mode rare-earth-doped fibers is given. A wide range of pulse-generation schemes comprising mode-locked fiber lasers, parametric pulse sources and hybrid diode-fiber amplifier sources are discussed. Both actively and passively mode-locked fiber lasers are described and their specific merits and operation regimes are elucidated. Techniques for improving the spectral quality and the output powers of diode-based systems based on amplification in rare-earth-doped fibers are also reviewed. Finally, applications are discussed and directions for future research are indicated. 相似文献
15.
Tip-enhanced Raman spectroscopy in reflection mode makes possible the nanoscale characterization of non-transparent samples, such as silicon, inaccessible in transmission mode. However, a particular feature of this technique is the superposition of the far-field Raman signal with the near-field one generated in the tip vicinity sometimes resulting in a low near-field-to-far-field contrast. By using a polarized configuration and orientation optimization of a (0 0 1) crystalline Si sample we were able to enhance significantly the contrast through reducing the far-field contribution, reaching a value of about 40. This contrast enhancement method can be applied in principle to any crystalline sample. 相似文献
16.
N. Naumov V. Petrovskiy E. Protsenko V. Yermachenko 《Applied physics. B, Lasers and optics》1997,65(4-5):589-593
4 gas laser with an intracavity absorbing cell is studied experimentally and theoretically at a modulation frequency approximately
equal to the intermode beat frequency. It is revealed that in the vicinity of the absorption-line centre the intensity of
every mode for certain system parameters displays resonance structures narrower than the homogeneous line width of the absorption
line. This occurs when the range of mode synchronization is near the absorption-line centre and its size is less than the
homogeneous width of the absorption line.
Received: 29 February 1996/Revised version: 4 February 1997 相似文献
17.
Optical properties of silver and gold semi-continuous films near the percolation threshold are investigated by scanning near field optical microscopy (SNOM) operating in the collection/transmission mode. The electromagnetic enhanced fields, due to plasmon-polariton localizations, are observed and the intensity distribution is shown to present high intensity variations that increase with the wavelength. The local fields are also demonstrated to be polarization dependent. The intensity distribution is investigated as function of the incident wavelength both for gold and silver films. The calculated probability distribution function (PDF) exhibits an exponential decay for large enhancement factors and is proved to be wavelength dependent. 相似文献
18.
SONG ZhongJu YUAN Ruo CHAI YaQin CHE Xin&LV Ping Key Laboratory on Luminescence Real-Time Analysis Ministry of Education College of Chemistry Chemical Engineering Key Laboratory of Eco-environments in Three Gorges Reservoir Region Southwest University Chongqing China 《中国科学B辑(英文版)》2011,(3)
An effective electrochemical signal amplification strategy based on enzyme membrane modification and redox probe immobilization was proposed to construct an amperometric immunosensor.L-cysteine@ferrocene functionalized chitosan,which possessed not only efficient redox-activity but also excellent film-forming ability,was coated on the bare glass carbon electrode. Moreover,the thiol groups(SH)in the ferrocenyl compound were used for gold nanoparticles immobilization via the strong bonding interaction,which co... 相似文献
19.
J. Dziesiaty M.U. Lehr P. Peka A. Klimakow S. Müller H.-J. Schulz 《The European Physical Journal B - Condensed Matter and Complex Systems》1998,4(3):269-277
ZnS:Ti crystals grown by different methods are investigated at low temperatures (2 K K) by electron paramagnetic resonance (EPR) and optical spectroscopies, mainly with regard to their photoluminescence properties,
including excitation and sensitisation spectra. The more familiar lattice-neutral Ti2+(d
2
) ion on a cubic site (AN) presents an isotropic EPR signal with g=1.928 observable up to 80 K. Signals of axial PN and AS sites are detected in the same temperature range. This Ti2+ ion exhibits the transition in emission, structured by no-phonon lines (NPL) of centres in various environments, with the AN site represented
at 3613 cm-1, and the 3
T
1
(F) and 3
T
1
(P) bands in excitation spectra. Substitutional Ti3+(d
1
) is identified by an anisotropic EPR spectrum at T = 3.5 K, indicating a quasistatic Jahn-Teller effect at the doubly degenerate 2
E(D) ground state, while in the first excited vibronic state a quasidynamic JT effect in the strain-split vibronic 2
E/2
A
2
manifold is found. A new luminescence band centred at 4500 cm-1 with NPL structures near 5000 cm-1 represents AN, PN and AS sites in the transition. Charge-transfer processes are described in a one-particle model, depicting the Ti3+/Ti2+ donor level at 12 900 cm-1 below the conduction-band edge.
Received: 3 October 1997 / Revised: 17 December 1998 / Accepted: 18 May
1998 相似文献
20.
Using a laterally oscillating all-metallic probe, a scanning capacitance microscope (SCM) has been used to yield an image
of the spatial derivative of the local capacitance, dC/dX, where C and X are the local capacitance and the axis of the probe
tip locus on the sample surface, respectively. Bias fields, except for the ultra-high-frequency fields used for sensing the
capacitance, are not necessary to detect the dC/dX signal, which yields an image delineating clearly the depletion region
due to the p–n junction. Simultaneously with the dC/dX image, the new SCM can give images of topography and dC/dV if an alternating
field V is applied between the probe and sample.
Received: 19 March 2001 / Accepted: 22 March 2001 / Published online: 27 June 2001 相似文献