Amplitude and chirp characterization of high-power laser pulses in the 5-fs regime

Abstract

Frequency-resolved optical gating (FROG) based on second-harmonic generation has been demonstrated to be capable of high-fidelity measurement of the electric-field envelope and of the temporal evolution of the instantaneous carrier frequency of 0.1-TW 5-fs pulses without the need for any correction for systematic experimental errors. At a 1-kHz repetition rate, pulse energies of a few microjoules are sufficient for reliable FROG characterization of pulses with durations down to the single-cycle regime. The results obtained reveal that carefully designed hollow-fiber chirped-mirror compressors are able to deliver high-power sub-10-fs pulses with a smooth Gaussianlike leading edge that has an intensity contrast of approximately 10(-2) .

Experimental and theoretical demonstration of validity and limitations in fringe-resolved autocorrelation measurements for pulses of few optical cycles

“…This result agrees with not only the calculated result of Fig. 6 but also previously reported results [2,3,4,5].…”

“…Moreover, we find that when pulse durations are measured around θ 40 • for case M-1 and around θ 20 • for case M-2, both apparent durations become shorter than correct pulse durations, as previously reported [2,3,4,5].…”

“…The former problem is difficult to solve in principle, but the latter may be avoided by comparing a measured FRAC trace with a calculated trace by use of its spectrum. Nevertheless, the measured pulse duration tends to be evaluated to be shorter [2,3,4,5] than that obtained by other measurement methods, for example, frequency-resolved optical gating (FROG) [2,4,6] and spectral phase interferometry for direct electric-field reconstruction (SPIDER) [7,8,11]. In addition, the measured pulse duration is sometimes evaluated to be shorter than that of its Fourier-transform-limited (TL) pulses.…”

Optical pulse compression to 50 fs by use of only a spatial light modulator for phase compensation

“…Optical pulses of ϳ5 fs have been generated directly from an oscillator 1,2 and external compression by use of a fused-silica fiber, [3][4][5] a capillary fiber filled with a noble gas, 6,7 or optical parametric amplification 8 for spectrum broadening. All these methods utilize chirped mirrors for chirp compensation.…”

“…To evaluate accurately the pulses that are thus generated, we used not only a fringe-resolved autocorrelator (FRAC) but also a second-harmonic generation (SH) frequency-resolved optical gating (FROG) apparatus. 4,5,7 …”