Abstract

Advances in ultrafast laser technology led to the generation of optical pulses that comprise less than 3 optical cycles within their FWHM directly from mode-locked lasers. As the pulse duration approaches the optical oscillation period, the phase of the electric field at pulse center, ψ, gains rapidly increasing significance. Simple considerations suggest that the evolution of nonlinear optical processes triggered by light pulses consisting of 1-3 oscillation cycles depend on and hence can be controlled by ψ. For instance, controlling the electronic wavepacket dynamics in atomic systems by phase-controlled ultrashort pulses will have important impacts on multiphoton ionization in the tunneling (or quasi-static) regime¹ as well as related phenomena, such as the generation of coherent soft X-rays^1,2 and XUV attosecond pulses.³

© 1996 IEEE