Figure 2
From: Direct compression of 170-fs 50-cycle pulses down to 1.5 cycles with 70% transmission
(a) Pressure dependent output pulse spectra for the 6-m-long HCF. (b) Second harmonic autocorrelation traces corresponding to the minimum pulse durations achieved from 1.7 to 2.4 bar. Each Gaussian fitting curve is compared with the minimum pulse duration fitting (5.1 fs at 2.2 bar) by area subtraction (gray area). (c) Compressed pulse durations as a function of the Ar pressure, in terms of FWHM derived from the Gaussian fittings.
