共查询到20条相似文献,搜索用时 15 毫秒
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R. M. Arkhipov M. V. Arkhipov A. V. Pakhomov I. Babushkin N. N. Rosanov 《Optics and Spectroscopy》2017,123(4):610-614
Collisions of unipolar subcycle pulses in a nonlinear resonant medium that coherently interact with it are studied theoretically. The dynamics of spatial polarization structures and population difference that the pulses induce in the medium are analyzed. A surprising feature is that the medium is capable of “remembering” the result of the interaction with the pulses and their collisions during times comparable to the polarization relaxation time. An analysis of the dynamics of light-induced structures makes it possible to judge the parameters of subcycle pulses at the times longer than the pulse duration, which, in the future, can be useful in their detection. 相似文献
3.
We have examined the propagation of femtosecond laser pulses in an absorbing dye solution through a short to a long range of propagation distance. The transmitted pulses show strong spectral shift and a superluminal to subluminal transition in the propagation velocity keeping its initial shape almost intact. It is verified that the peak velocity is well described by a modified group velocity v(S) defined within the framework of the saddle-point method as well as by a recent prediction of the net group delay of surviving frequency. 相似文献
4.
提出了磁光光纤Bragg光栅的理论模型,给出了圆偏振光在磁光光纤光栅中传播的非线性耦合模方程. 研究表明,在磁光光纤Bragg光栅中,光栅引起正反传播方向的导波光发生耦合,法拉第效应引起磁圆双折射效应,而非线性效应则将左旋和右旋圆偏振光耦合在一起,它们的共同作用可使双稳态状态发生反转、非线性光控光开关阈值功率降低. 与传统光纤光栅相比,利用左旋和右旋磁圆偏振光之间的交叉相位调制实现的脉冲整形具有磁光偏置可调特性,为基于磁光光纤光栅的动态灵活全光3R再生器的研制提供了理论基础.
关键词:
磁光光纤Bragg光栅
圆偏振光
脉冲整形 相似文献
5.
Horst F. Hoekstra H. J. W. M. Driessen A. Popma Th. J. A. 《Optical and Quantum Electronics》1998,30(5-6):335-341
A two-dimensional time domain finite difference beam propagation method, based on the slowly varying envelope approximation is presented. Expressions to correct this approximation and to include third-order non-linear effects are given. The method is applied on solitary waves in a non-linear Bragg reflector, assuming realistic materials parameters. 相似文献
6.
Noise reduction in a multiwavelength distributed Bragg reflector fiber laser was demonstrated. A 20 dB reduction of in-phase intensity noise was achieved by using negative feedback to modulate the drive current of the laser pump diode. Strategies for reducing antiphase noise components are discussed. 相似文献
7.
A. P. Kazantsev V. S. Smirnov V. P. Sokolov A. N. Tumaikin 《Applied physics. B, Lasers and optics》1982,27(2):83-91
The space-time properties of the correlator of the light intensities scattered from resonant atoms are studied. It is shown that in measuring such a correlator by the method of optical shifts, an appreciable contribution appears from the anomalous correlator of the scattered field amplitudes. It is simple to observe this correlator in the field of a standing wave by measuring the correlation of oppositely scattered rays. The spectral and polarization properties of such a correlator are studied. Its investigation is of interest for high-resolution spectroscopy because it allows information to be obtained on the natural width of a line in conditions of strong Doppler broadening. It is important to stress that this is possible in a linear approximation with respect to the strength of the external field in contrast to the methods of laser spectroscopy based on nonlinear effects. 相似文献
8.
T. Tanbun-Ek 《Optical and Quantum Electronics》1988,20(6):485-492
An analysis of the sensitivity and low-frequency intensity noise characteristics of Bragg reflector lasers is given. It is found that Bragg reflector lasers have increased sensitivity to reflected light for low grating coupling strength (l) and is similar to that of Fabry-Perot lasers except for highl values. Also, the intensity noise can be reduced by operating the device at high injection level. 相似文献
9.
A. Buchleitner K. Sacha D. Delande J. Zakrzewski 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》1999,5(2):145-157
We present a semiclassical analysis of the dynamics of Rydberg states of atomic hydrogen driven by a resonant microwave field
of linear polarization. The semiclassical quasienergies of the atom in the field are found to be in very good agreement with
the exact quantum solutions. The ionization rates of individual eigenstates of the atom dressed by the field reflect their
quasiclassical dynamics along classical periodic orbits in the near integrable regime, but exhibit a transition to nonspecific
rates when global chaos takes over in phase space. We concentrate both on the principal resonance where the unperturbed Kepler
frequency is equal to the driving field frequency and on the higher primary resonance The latter case allows for the construction of nondispersive wave packets which propagate along Kepler ellipses of intermediate
eccentricity.
Received: 23 June 1998 / Accepted: 10 November
1998 相似文献
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《中国物理 B》2015,(11)
Planar Bragg reflector operating in the sub-terahertz wavelength installed at the upstream end of a sheet beam backward wave oscillator(BWO) is very promising to minimize the whole circuit structure and make it more compact. In this paper, a sub-terahertz wavelength(0.18–0.22 THz) tunable planar Bragg reflector is numerically analyzed by using multi-mode coupling theory(MCT). The operating mode TE10 and dominant coupling mode TE01 are mainly considered in this theory. Reflection and transmission performance of the reflector are demonstrated in detail and the results, in excellent agreement with the theoretical analysis and simulation, are also presented in this paper. Self- and cross-coupling coefficients between these two modes are presented as well. The reflector behaviors with different Bragg dimensions are discussed and analyzed in the 0.16–0.22 THz range. The analysis in this paper can be of benefit to the design and fabrication of the whole BWO circuit. 相似文献
12.
Ching-Liang Wei Ying-Chung Chen Chien-Chuan Cheng Kuo-Sheng Kao 《Applied Physics A: Materials Science & Processing》2008,91(3):501-506
Bright and efficient stacked color-tunable organic light emitting devices (OLEDs) using an intermediate Al/Au electrode have
been reported. The effects of the thicknesses of Al and Au layers on the luminance characteristics have been comprehensively
studied. After optimization, the bottom-emission single-unit OLED of 4,4′,4′′-Tris(N-3-methylphenyl-N-phenyl-amino) triphenylamine/N,N′-diphenyl-N,N′-bis(1-naphthyl)-(1,1′-biphenyl)-4,4′-diamine/tris(8-hydroxyquinoline) aluminum has a maximum luminance efficiency (ηL) of 3.37 cd/A by using Al/Au as the cathode and 2.92 cd/A by using Al/Au as the anode. Meanwhile, by introducing the optimized
intermediate Al/Au electrode into the stacked color-tunable (red to blue) OLEDs, a red unit with maximum ηL of 4.73 cd/A and a blue unit with maximum ηL of 3.96 cd/A have been obtained. The color can be tuned efficiently along a linear route from pure red with the Commission
Internationale de l’Eclairage (CIE) coordinates of (0.662, 0.330) to sky blue with the CIE coordinates of (0.155, 0.340).
This scheme can be a potential candidate for achieving high-brightness and efficient stacked color-tunable OLEDs.
PACS 78.60.Fi; 78.66.Qn; 81.05.Lg; 85.30.De 相似文献
13.
Fabre CM Cheiney P Gattobigio GL Vermersch F Faure S Mathevet R Lahaye T Guéry-Odelin D 《Physical review letters》2011,107(23):230401
We report on the experimental study of a Bragg reflector for guided, propagating Bose-Einstein condensates. A one-dimensional attractive optical lattice of finite length created by red-detuned laser beams selectively reflects some velocity components of the incident matter wave packet. We find quantitative agreement between the experimental data and one-dimensional numerical simulations and show that the Gaussian envelope of the optical lattice has a major influence on the properties of the reflector. In particular, it gives rise to multiple reflections of the wave packet between two symmetric locations where Bragg reflection occurs. Our results are a further step towards integrated atom-optics setups for quasi-cw matter waves. 相似文献
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L. Dunajský 《Czechoslovak Journal of Physics》1962,12(9):665-669
The tensor of reflected and refracted light was first introduced into the principal axes and then the latter were transformed into thep ands direction of the electric field strength. The amplitude coefficient of thep-components of refracted light has different forms depending on which complex unit vector is unit with respect to the square or the absolute value. The energy coefficient has the same value in both cases.
, p s . p- , . .相似文献
15.
Ostojic GN Zaric S Kono J Strano MS Moore VC Hauge RH Smalley RE 《Physical review letters》2004,92(11):117402
Wavelength-dependent pump-probe spectroscopy of micelle-suspended single-walled carbon nanotubes reveals two-component dynamics. The slow component (5-20 ps), which has not been observed previously, is resonantly enhanced whenever the pump photon energy coincides with an absorption peak and we attribute it to interband carrier recombination, whereas we interpret the always-present fast component (0.3-1.2 ps) as intraband carrier relaxation in nonresonantly excited nanotubes. The slow component decreases drastically with decreasing pH (or increasing H+ doping), especially in large-diameter tubes. This can be explained as a consequence of the disappearance of absorption peaks at high doping due to the entrance of the Fermi energy into the valence band, i.e., a 1D manifestation of the Burstein-Moss effect. 相似文献
16.
《Optics Communications》2002,201(1-3):139-144
The transmission matrix model (TMM) has been used to simulate the tuning behaviour of a sampled-grating distributed Bragg reflector (SG-DBR) laser for the first time, to the best of our knowledge. The model is able to describe all details of the spontaneous emission spectrum below threshold and yields results in good qualitative agreement with experiment. 相似文献
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Dual-wavelength distributed Bragg reflector semiconductor laser based on a composite resonant cavity 下载免费PDF全文
We report a monolithic integrated dual-wavelength laser diode based on a distributed Bragg reflector (DBR) composite resonant cavity. The device consists of three sections, a DBR grating section, a passive phase section, and an active gain section. The gain section facet is cleaved to work as a laser cavity mirror. The other laser mirror is the DBR grating, which also functions as a wavelength filter and can control the number of wavelengths involved in the laser action. The reflection bandwidth of the DBR grating is fabricated to have an appropriate value to make the device work at the dual-wavelength lasing state. We adopt the quantum well intermixing (QWI) technique to provide low-absorption loss grating and passive phase section in the fabrication process. By tuning the injection currents on the DBR and the gain sections, the device can generate 0.596 nm-spaced dual-wavelength lasing at room temperature. 相似文献
19.
Linh Mai Van-Su Pham Giwan Yoon 《Applied Physics A: Materials Science & Processing》2009,95(3):667-671
In this paper, we studied ZnO-based film bulk acoustic resonator (FBAR) device fabricated on a specially designed multilayered
Bragg reflector part. Very thin chromium adhesion layers (0.03 μm thick) were additionally deposited to improve the quality
of the Bragg reflector and some thermal treatments were performed to improve the resonant characteristics of the FBAR device.
At the operating frequency of ∼2.7 GHz, excellent resonant characteristics were observed in terms of return loss and quality
factor, and effective electromechanical coupling coefficient. 相似文献
20.
We present analysis of the distributed Bragg reflector in a microring resonator (DBR-MRR) structure. With appropriate design
parameters, the device can closely reproduce the reflectance spectrum of a sampled grating distributed Bragg reflector (SGDBR).
By inserting the grating inside a microring resonator, the structure is much more compact than an SGDBR, suppresses side mode
ripples near each peak, and offers better control over its full width half maximum (FWHM). The device is expected to have
applications in compact tunable lasers and other planar photonic devices. 相似文献