Absolute phase control of intense few-cycle pulses and steering the atomic-scale motion of electrons

In the past few years, ultrafast laser technology has developed to such a degree that the phase of a pulse under its envelope is now a meaningful measurable quantity. Many experiments now require the use of pulses with a fixed phase. The reliable production of such pulses, over extended periods of time, is of key importance to many areas of science. The central theme of this thesis is the generation of intense phase-controlled few-cycle optical pulses and their applications. This thesis reports on substantial improvements made in the generation of carrier-envelope phase-controlled pulses. Measurements performed show the accuracy to which absolute phase can be controlled has been improved to a unpreceded level. Also, the period of time over which such high accuracy measurements could be performed was extended by more than a factor of five, such that carrier-envelope phase-sensitive measurements that take longer than 24 hours without any breaks are now possible. With these tools at hand, physical processes that take place on sub-femtosecond time scales can be precisely measured, and control over the motion of bound electrons is possible. In this thesis, a report on the first demonstration of the latter is presented: In the dissociation of the D_2^+ -ion, control over the localisation of the remaining electron is demonstrated