共查询到20条相似文献,搜索用时 62 毫秒
1.
We propose a novel method for completely characterizing ultrashort pulses at extreme-ultraviolet (XUV) wavelengths by adapting the technique of spectral phase interferometry for direct electric-field reconstruction to this spectral region. Two-electron wave packets are coherently produced by photoionizing atoms with two time-delayed replicas of the XUV pulse. For one of the XUV pulses, photoionization occurs in the presence of a strong infrared pulse that ponderomotively shifts the binding energy, thereby providing the spectral shear needed for reconstruction of the spectral phase of the XUV pulse. 相似文献
2.
We introduce a noninterferometric single beam method to characterize and compensate the spectral phase of ultrashort femtosecond pulses accurately. The method uses a pulse shaper that scans calibrated phase functions to determine the unknown spectral phase of a pulse. The pulse shaper can then be used to synthesize arbitrary phase femtosecond pulses or it can introduce a compensating spectral phase to obtain transform-limited pulses. This method is ideally suited for the generation of tailored spectral phase functions required for coherent control experiments. 相似文献
3.
An extension of the well-known technique for spectral phase interferometry for direct electric-field reconstruction (SPIDER) has been developed that permits the reconstruction of the spectral amplitude and the spectral phase of ultrashort laser pulses from the acquisition of only one spectrum. Temporal intensity and temporal phase can therefore easily be retrieved. The characterization of pulses from a Ti:sapphire oscillator by use of an extended SPIDER is discussed. Advantages and drawbacks of the modified technique are also discussed. 相似文献
4.
Mid-infrared ultrashort pulses of 9.2-microm center wavelength are characterized in both amplitude and phase. This is achieved by use of a variant of spectral phase interferometry for direct electric field reconstruction in which spectral interferometry has been replaced with time-domain interferometry, a technique that is well suited for infrared pulses. The setup permits simultaneous recording of the second-order interferometric autocorrelation, thus providing an independent check on the retrieved spectral phase. 相似文献
5.
We propose a technique for time resolution of the polarization state of ultrashort light pulses that also provides the overall time-varying phase of the pulse. This method is based on a spectral polarimetric analysis of the pulse after propagation through a Kerr medium. The feasibility of this method is demonstrated both numerically and experimentally. 相似文献
6.
We present what we believe to be a new version of spectral phase interferometry for direct electric field reconstruction (SPIDER) using only a single-phase and polarization controlled laser beam. Two narrow pulses and one broadband pulse are selected out of an ultrafast laser pulse by a polarization and phase control technique to generate second harmonic generation (SHG) signals, which are equivalent to a spectral shear interferogram in the conventional SPIDER method. The spectral phase of the broadband laser pulse is extracted analytically with double quadrature spectral interferometry (DQSI). An arbitrary spectral phase can be retrieved with great precision and compensated in situ at the sample position of a microscope. This new method requires no separate reference beam and is suitable for nonlinear optical microscopy with a phase controlled laser pulse. 相似文献
7.
We analyze the characterization of strongly chirped pulses by spectral phase interferometry for direct electric-field reconstruction (SPIDER). We show how to extend the working range of this technique for these relevant cases and derive correction factors for typical operating parameters. The results are straightforward to implement in the calculation algorithms. We demonstrate the validity of this technique by characterizing numerically and experimentally pulses with a known spectral phase profile. 相似文献
8.
We propose and experimentally demonstrate a method for fiber dispersion measurement based on the modulation of laser pulses stretched by the fiber under test. The measured spectrum of the modulated pulses is the result of the interference between the stretched pulse spectra shifted by the modulation harmonics. The interference pattern is processed as in Fourier transform spectral interferometry. Unlike to conventional spectral interferometry, environmental conditions do not affect the interferogram due to the lack of any interferometer; additionally, large dispersions can be characterized by the method proposed. Its high accuracy is demonstrated in experimental comparison with the widely used phase shift technique. 相似文献
9.
Modified spectrum autointerferometric correlation (MOSAIC) for single-shot pulse characterization 总被引:2,自引:0,他引:2
A method for generation of the modified spectrum autointerferometric correlation that allows single-shot pulse characterization is demonstrated. A sensitive graphical representation of the ultrashort pulse phase quality is introduced that delineates the difference between the presence of temporal and spectral phase distortions. Using these schemes, full-field reconstruction of ultrashort laser pulses is obtained in real time using an efficient iterative technique. 相似文献
10.
We present a new method for the measurement of the phase of ultrashort optical pulses with high spectral resolution. This
employs an interferometer with a monochromator in one arm. Two detectors operating in single photon and two-photon absorption
regimes monitor the output from the interferometer. Comparison of the signals from the two detectors gives a measurement of
the phase of the light pulse. The principles underpinning this technique are discussed and the experimental application to
picosecond pulses is demonstrated. 相似文献
11.
A new technique of spectral compression of femtosecond pulses, based on their frequency intermodulation in the frequency mixing process, is demonstrated experimentally. In the exploited phenomenon of frequency intermodulation the phase of the reference pulse is superimposed on the signal instead of phase self- or cross-modulation used in traditional spectral compressors. In the process of frequency mixing a twelve-fold aberration-free spectral compression of 100 fs pulses has been achieved experimentally. 相似文献
12.
The Keldysh theory of above-threshold ionization (ATI) is applied to few-cycle laser pulses in order to explore the potential of a recently published new method to measure "carrier-envelope phase difference" phenomena. In this experiment, the carrier-envelope phase difference dependent left-right asymmetry of few-cycle ATI was measured and investigated with a correlation technique. Here, we explore spectral features of the asymmetry, present a theoretical analysis of the experiment, and establish a method to determine the duration of few-cycle pulses whose carrier-envelope phase differences are not controlled. 相似文献
13.
Kornelis W Biegert J Tisch JW Nisoli M Sansone G Vozzi C De Silvestri S Keller U 《Optics letters》2003,28(4):281-283
We describe a method of characterizing ultrashort optical pulses that is based on the technique of spectral phase interferometry for direct electric-field reconstruction and is capable of simultaneously measuring the amplitude and the phase of the electric field of a sub-10-fs pulse at kilohertz acquisition rates on a single-shot basis. Use of this technique results in a dramatic increase (>50x) in acquisition rate compared with that of existing diagnostics for full E-field characterization and opens the door to a range of new experiments in which shot-to-shot phase and amplitude fluctuations are studied at kilohertz rates. 相似文献
14.
M. Roth M. Mehendale A. Bartelt H. Rabitz 《Applied physics. B, Lasers and optics》2005,80(4-5):441-444
This work demonstrates a simple method for ultraviolet (UV) acousto-optical pulse shaping of both spectral amplitude and phase. A fused-silica acousto-optical modulator is used to ensure high transmission and a high damage threshold at 400-nm center wavelength. The technique eliminates complications associated with the parametric transfer of the spectral phase of near-infrared pulses through a nonlinear process out to UV wavelengths, by separating the frequency doubling and shaping processes. Three illustrative applications of phase control are presented: the compensation of material dispersion, the generation of multiple pulse trains, and the generation of arbitrarily shaped pulse trains. Self-diffraction frequency-resolved optical gating is used to characterize the success of the technique. 相似文献
15.
We demonstrate a simple, all-optical, fiber-based method for characterizing the spectral amplitude and phase of ultrafast pulses using a differential tomographic measurement realized via four-wave mixing. The technique is applied to subpicosecond pulses in the C-band of the telecommunication spectrum. Characterization of amplified pulses and propagation through dispersive media is demonstrated and compared with autocorrelation measurements and calculated predictions. We show how our approach can be extended to larger bandwidths in similar systems, extending tomographic reconstruction of coherent fields to nearly an octave of bandwidth while maintaining a robust, waveguide-based geometry. 相似文献
16.
A very simple self-referenced, linear pulse-characterization technique based on spectral phase reconstruction by frequency-domain signal differentiation is introduced. This technique can be implemented using electro-optic intensity modulation of the pulse under test with a synchronized RF sinusoid. The pulse spectral phase profile can be accurately and unambiguously reconstructed from only two measured energy spectra, i.e., at the input and at the output of the modulator, using a direct analytic equation. The method is experimentally demonstrated by precisely characterizing microwatt-power picosecond pulses after linear dispersion through short sections (50-700 m) of conventional single-mode fiber. 相似文献
17.
Relative carrier-envelope phase dependence of resonant propagation of two-colour femtosecond pulses in V-type atomic medium
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Using numerical solution of the full Maxwell--Bloch
equations, which is obtained by the finite-difference time-domain
method and the iterative predictor--corrector method, we investigate
the modulation effect of relative carrier--envelope phase
(hereinafter referred to as the relative phase) on resonant
propagation of two-colour femtosecond ultrashort laser pulses in a
V-type three-level atomic medium. It is found that the pulse
splitting occurs for a smaller value of relative phase; when the
value of relative phase increases to a certain value, only the
variation of pulse shape is present and the pulse splitting does not
occur any more; moreover, when the value of relative phase is
smaller, the pulse group velocity is larger. The relative phase also
has an obvious effect on population and spectral property. Different
population transfers can be realized by adjusting the value of
relative phase. Generally speaking, for the pulses with smaller
areas their spectral strengths and frequency ranges decrease
obviously with the value of relative phase increasing; for the
pulses with larger areas, with value of the relative phase
increasing, their spectral strengths decrease remarkably but the
relative strengths of the higher frequency components increase
significantly, while the spectral frequency range is not varied
evidently. 相似文献
18.
Doubled femtosecond laser pulses in-line are needed in the collinear pump-probe technique, collinear second harmonic generation frequency-resolved optical gating (SHG FROG) and the spectral phase interferometry for direct electric-field reconstruction (SPIDER), etc. Normally, it is generated by using a Michelson's structure. In this paper, we proposed a novel structure with two-layered reflective Dammann gratings and the reflective mirrors to generate doubled femtosecond laser pulses in line without transmission optical elements. Angular dispersion and spectral spatial walk-off are both compensated. In addition, this structure can also compress the positive chirped pulse, which cannot be realized with a Michelson's structure. By adopting triangular grating and blazed gratings, the efficiency of the system would in principle be increased as the Michelson's scheme. Experiments demonstrated that this method should be an alternative approach for generation of the double compressed pulses of femtosecond laser for practical applications. 相似文献
19.
We propose and demonstrate a novel method for the elimination of arbitrary frequency chirp from short optical pulses. The technique is based on the combination of two cascaded second-order nonlinearities in two individual periodically poled lithium niobate waveguides. The proposed scheme operates independently of the spectral phase characteristics of the input pulse, producing a near-transform-limited output. 相似文献
20.
We characterize ultrashort mid-infrared pulses through upconversion by using the stretched pulses obtained from the uncompressed output of a chirped-pulse amplifier. The power spectrum thus translated into the visible region can be readily measured with a standard silicon CCD camera-based spectrometer. The spectral phase is also characterized by a variant of zero-added-phase spectral phase interferometry for direct electric field reconstruction. This is a general method that provides a multiplex advantage over conventional infrared detector array-based methods. 相似文献