Direct generation of highly phase-matched isolated attosecond pulses using multi-mJ, carrier-envelope phase stabilized, few-cycle laser pulses

In this paper, the author have realized a multi-mJ few cycle laser with a stabilized carrier envelope phase (CEP) and the phase-matching between the few cycle pulses and high harmonics. This became possible by stabilizing CEP actively with two feedback loops and by blocking mechanical vibrations on the laser system thoroughly. To realize the phase matching between the few cycle pulses and the high harmonics, a gas cell was used, with which one can control the condition of the nonlinear medium freely and precisely. Through the phase matching process, the supercontinuum component of the harmonics can be selected without any use of bandpass filters.