共查询到20条相似文献,搜索用时 203 毫秒
1.
利用复q参数法,研究了几周期线性啁啾脉冲高斯光束在自由空间中的传播,在振幅零阶和相位一阶近似的条件下,得到其载波相位的解析公式,该公式的显著特点是载波相位与线性啁啾系数无关。研究了载波相位在传播方向的分布,并与数值计算方法比较,结果表明,啁啾系数在-1~1的范围内,在光轴附近,其载波相位解析公式结果与数值结果符合很好。 相似文献
2.
We theoretically investigate carrier-envelope phase dependence of few-cycle ultrashort laser pulse propagation in a polar molecule medium. Our results show that a soliton pulse can be generated during the two-photon resonant propagation of few-cycle pulse in the polar molecule medium. Moreover, the main features of the soliton pulse, such as pulse duration and intensity, depend crucially on the carrier-envelope phase of the incident pulse, which could be utilized to determine the carrier-envelope phase of a few-cycle ultrashort laser pulse from a mode-locked oscillator. 相似文献
3.
We obtain direct stabilization of the carrier-envelope phase for a standard x-folded geometry, octave-spanning, Ti:sapphire laser. The in-loop accumulated carrier-envelope phase error is 0.175 rad (1.65 mHz to 102 kHz). Intracavity continuum generation, which is responsible for the octave bandwidth, is characterized through measurement of the beam parameters. 相似文献
4.
We investigate coupling mechanisms between the amplitude and the carrier-envelope offset phase in mode-locked lasers. We find that nonlinear beam steering in combination with the intracavity prism compressor is the predominant mechanism that causes amplitude-to-phase conversion in our laser. A second mechanism, induced by self-steepening, is also identified. These mechanisms are important for stabilizing the carrier-envelope offset phase and also explain the extremely low pulse-to-pulse energy fluctuations observed in some lasers with carrier-envelope lock. The coupling mechanisms described have important implications for applications of few-cycle optical pulses. 相似文献
5.
M. Nisoli G. Sansone S. Stagira J.-P. Caumes C. Vozzi S. De Silvestri M. Pascolini L. Poletto P. Villoresi G. Tondello 《Applied physics. B, Lasers and optics》2004,78(7-8):873-877
Recently the role of the carrier-envelope phase of few-optical-cycle light pulses on high-order harmonic generation has been experimentally observed. By using a three-dimensional nonadiabatic propagation model, we show that the observed carrier-envelope phase dependence of the spectral characteristics of the harmonic radiation is essentially a single-atom effect. Nonadiabatic single-atom response has been calculated in the framework of the saddle-point approximation. PACS 42.65.Ky; 42.65.Re; 42.50.Hz 相似文献
6.
Kremer M Hofrichter C Fischer B Sharma V Camus N Pfeifer T Moshammer R Ullrich J 《Optics letters》2011,36(8):1455-1457
A systematic experimental study is performed to examine the f-2f technique for sweeping the carrier-envelope phase (CEP) of few-cycle laser pulses by changing the amount of positive dispersion in the extracavity beam path. Slightly changing the dispersion not only changes the CEP but affects the entire spectral-phase function. As a result, large discrepancies are found between the true CEP as independently measured with a stereo-above-threshold-ionization spectrometer and the CEP detected by an f-2f interferometer when sweeping the phase with glass wedges. A new CEP-stabilization scheme is proposed and experimentally shown to significantly improve the performance of CEP sweeping. 相似文献
7.
Generation of intense,carrier-envelope phase-locked few-cycle laser pulses through filamentation 总被引:3,自引:0,他引:3
Intense, well-controlled light pulses with only a few optical cycles start to play a crucial role in many fields of physics, such as attosecond science. We present an extremely simple and robust technique to generate such carrier-envelope offset (CEO) phase locked few-cycle pulses, relying on self-guiding of intense 43-fs, 0.84 mJ optical pulses during propagation in a transparent noble gas. We have demonstrated 5.7-fs, 0.38 mJ pulses with an excellent spatial beam profile and discuss the potential for much shorter pulses. Numerical simulations confirm that filamentation is the mechanism responsible for pulse shortening. The method is widely applicable and much less sensitive to experimental conditions such as beam alignment, input pulse duration or gas pressure as compared to gas-filled hollow fibers. PACS 45.65.Ky; 42.65.Re 相似文献
8.
Electromagnetic Gaussian Schell-model (EGSM) beam with twist phase (i.e., twisted EGSM beam) is introduced as an extension of its scalar version based on the unified theory of coherence and polarization. We show how analytical paraxial propagation formulae of isotropic and anisotropic EGSM beams passing through a general astigmatic ABCD optical system can be modified in the presence of the twist phase. Numerical examples demonstrate that the twist phase affects the spectral density, the state of coherence, and the degree of polarization of EGSM beams on propagation. 相似文献
9.
10.
Influence of spatiotemporal coupling on the capture-and-acceleration-scenario vacuum electron acceleration by ultrashort pulsed laser beam
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This paper investigates the properties of the ultrashort pulsed beam aimed to the
capture-and-acceleration-scenario (CAS) vacuum electron acceleration. The result
shows that the spatiotemporal distribution of the phase velocity, the longitudinal
component of the electric field and the acceleration quality factor are
qualitatively similar to that of the continuous-wave Gaussian beam, and are slightly
influenced by the spatiotemporal coupling of the ultrashort pulsed beam. When the
pulse is compressed to an ultrashort one in which the pulse duration TFWHM
<5T0, the variation of the maximum net energy gain due to the
carrier-envelope phase is a crucial disadvantage in the CAS acceleration process. 相似文献
11.
Single-shot measurement of carrier-envelope phase changes by spectral interferometry 总被引:3,自引:0,他引:3
Kakehata M Takada H Kobayashi Y Torizuka K Fujihira Y Homma T Takahashi H 《Optics letters》2001,26(18):1436-1438
We demonstrated single-shot measurements of spectral interference between a white-light continuum generated in a hollow-fiber and its second harmonic. The interference has information on the carrier-envelope phase of an input pulse to the fiber and the time delay of the blue wing of the continuum. By analyzing the observed spectral interference, we estimated shot-by-shot changes of the carrier-envelope phase. This method is useful for determining the carrier-envelope phase changes of a low-repetition-rate, high-intensity laser. 相似文献
12.
We theoretically investigate the dependence of the electron tunneling on the carrier-envelope phase of a few-cycle laser pulse in a coupled double-quantum-dot system, and we show that the electron tunneling between coupled quantum dots is very sensitive to the carrier-envelope phase under a change of the parameters of the system. This in turn provides an additional means to measure the carrier-envelope phase of a laser pulse at lower laser intensity regime in the solid-state nanostructure. 相似文献
13.
L. Bergé C.-L. Soulez C. Köhler S. Skupin 《Applied physics. B, Lasers and optics》2011,103(3):563-570
We numerically study the influence of the initial carrier-envelope phase (CEP) on the filamentation of ultrashort laser pulses
in noble gas. Emphasis is put on the CEP-induced changes of pulses that reach their clamping intensity during near-cycle self-compression.
In other propagation regimes, the CEP does not significantly alter the pulse evolution. Our results indicate that third-harmonic
generation, compared to plasma generation, is dominant in driving these changes. Finally, the stability of the filament CEP
against shot-to-shot fluctuations is examined. 相似文献
14.
15.
Haifeng Yao Yueping Niu Yandong Peng Shangqing Gong 《Optics Communications》2011,284(16-17):4059-4063
We investigate the nonlinear propagation of few-cycle rectangular laser pulses on resonant intersubband transitions in semiconductor quantum wells using an iterative predictor–corrector finite-difference time-domain method. An initial 2π rectangular pulse will split into Sommerfeld–Brillouin precursors and a self-induced transparency soliton during the course of propagation. The duration of generated soliton depends on the carrier-envelope phase of the incident pulse. In our case, not only the near-resonant frequency components but also the low frequency components could contribute to the generation of the soliton pulse when the condition of multi-photon resonance is satisfied. The phase-sensitive property of the solitons results from the phase-dependent distribution of high and low frequency sidebands of few-cycle rectangular pulses. 相似文献
16.
Two-cycle optical pulses with duration of 5 fs and energy of 0.7 mJ have been generated at 1 kHz by compressing the 38 fs laser pulses from a carrier-envelope phase (CEP) controlled Ti:sapphire laser system through a cascade filamentation compression technique. A simple and effective method is developed to suppress multiple filament formation and stabilize a single filament by inserting a soft aperture with an appropriate diameter into the driving laser beam prior to focusing, resulting in an excellent compressed beam quality. The good beam quality and potentially higher peak power make this ultrashort laser pulse source a significant tool for high-field physics applications. 相似文献
17.
18.
The feed-forward technique has recently revolutionized carrier-envelope phase (CEP) stabilization, enabling unprecedented values of residual phase jitter. Nevertheless, its demonstrations have hitherto remained in a proof-of-principle state. Here we show that pulse quality and power issues can be solved, leading to few-cycle pulses with good beam quality. Making use of stable interferometers, we achieve day-long CEP-stable operation of the setup. Out-of-loop RMS phase noise amounts to less than 30 mrad in 20 s, with more than 24 h of CEP-locked operation being demonstrated. 相似文献
19.
The carrier-envelope phase of the pulse train emitted by a 10-fs mode-locked laser has been stabilized such that carrier-envelope phase coherence is maintained for at least 150 s (measurement limited). The phase coherence time was measured independently of the feedback loop. 相似文献
20.
Sansone G Vozzi C Stagira S Pascolini M Poletto L Villoresi P Tondello G De Silvestri S Nisoli M 《Physical review letters》2004,92(11):113904
So far the role of the carrier-envelope phase of a light pulse has been clearly experimentally evidenced only in the sub-6-fs temporal regime. Here we show, both experimentally and theoretically, the influence of the carrier-envelope phase of a multi-optical-cycle light pulse on high-order harmonic generation. For the first time, we demonstrate that the short and long electron quantum paths contributing to harmonic generation are influenced in a different way by the pulse carrier-envelope phase. 相似文献