Ultrafast Light Pulses

START project Y 44 Ultrafast Light Pulses Ference KRAUSZ 28.06.1996 This project aims at advancing the state of the art of ultrashort-pulse lasers and pushing the limits of nonlinear optics as well as time-resolved spectroscopy. Particular emphasis is placed on the generation, characterization, and applications of laser pulses in which the electric and magnetic fields perform merely a few oscillations cycles. The evolution of the fields in few-cycle light wave packets sensitively depends on the "absolute" phase of light, which could not be measured in ultrafast optics so far. Getting access to this "new parameter" and developing techniques for its control in ultrashort-pulse laser oscillators (pulse duration < 10 fs, 1 fs = 10-15 s) is one of the major objectives of the project. Simultaneously, novel concepts are tested and implemented for boosting the energy of sub-10-fs laser pulses by several orders of magnitude upon preserving their bandwidth to produce few-cycle light with peak powers up to several terawatts. Intense phase-controlled light "transients" open up the way to triggering, tracing, and even controlling a wide range of processes in strong-field atomic physics as well as relativistic plasma nonlinear optics. Striking consequences include the efficient production and precise temporal control of high-order harmonic emission from few-cycle-driven atoms, which may result in isolated (1pulse/laser pulse) attosecond XUV/X-ray pulses, and the generation of multi-MeV electron bursts of few fs duration from few-cycle-produced relativistic plasmas. These ultrashort-duration high-energy, short-wavelength electromagnetic and electron pulses pave the way towards entirely new spectroscopies. Tracing nuclear motion in chemical processes, inner-shell atomic electron relaxation dynamics and the temporal evolution of the wave function of bound electrons with a resolution of a few femtoseconds to tens of attoseconds constitute fascinating and challenging long-term perspectives, which provide motivation for pursuing the above described research.