Spectral and temporal structure in high harmonic emission from ionizing atomic gases

Publisher Website
Google Scholar
Abstract
We show that high harmonic generation in ionizing atomic gases should be accompanied by an intensity-dependent harmonic phase that under realistic experimental conditions will lead to a readily observable blue shift and line splitting in the midplateau harmonics. The origins of the observed blue shift and line splitting are detailed. We also show that midplateau harmonics with a duration of only a few femtoseconds can be generated by combining the intensity dependences of the atomic nonlinear polarizability and the free-electron-induced phase mismatch.