Over the last few years, there has been a convergence between the fields of ultrafast science, nonlinear optics, optical frequency metrology, and precision laser spectroscopy. These fields have been developing largely independently since the birth of the laser, reaching remarkable levels of performance. On the ultrafast frontier, pulses of only a few cycles long have been produced, while in optical spectroscopy, the precision and resolution have reached one part in Although these two achievements appear to be completely disconnected, advances in nonlinear optics provided the essential link between them. The resulting convergence has enabled unprecedented advances in the control of the electric field of the pulses produced by femtosecond mode-locked lasers. The corresponding spectrum consists of a comb of sharp spectral lines with well-defined frequencies. These new techniques and capabilities are generally known as “femtosecond comb technology. ” They have had dramatic impact on the diverse fields of precision measurement and extreme nonlinear optical physics. The historical background for these developments is provided in the Foreword by two of the pioneers of laser spectroscopy, John Hall and Theodor Hänsch. Indeed the developments described in this book were foreshadowed by Hänsch’s early work in the 1970s when he used picosecond pulses to demonstrate the connection between the time and frequency domains in laser spectroscopy. This work complemented the advances in precision laser stabilization developed by Hall.

This thesis presents first successful experiments to carrier-envelope-phase stabilize a high-power mode-locked thin-disk oscillator and to compress the pulses emitted from this laser to durations of only a few-optical cycles. Moreover, the monograph introduces several methods to achieve power-scalability of compression and stabilization techniques. All experimental approaches are compared in detail and may serve as a guideline for developing high-power waveform controlled, few-cycle light sources which offer tremendous potential to exploit extreme nonlinear optical effects at unprecedentedly high repetition rates and to establish table-top infrared light sources with a unique combination of brilliance and bandwidth. As an example, the realization of a multi-Watt, multi-octave spanning, mid-infrared femtosecond source is described. The thesis starts with a basic introduction to the field of ultrafast laser oscillators. It subsequently presents additional details of previously published research results and establishes a connection between them. It therefore addresses both newcomers to, and experts in the field of high-power ultrafast laser development.

The open access journal Micromachines invites manuscript submissions for the Special Issue “Silicon Photonics Bloom”. The past two decades have witnessed a tremendous growth of silicon photonics. Lab-scale research on simple passive component designs is now being expanded by on-chip hybrid systems architectures. With the recent injection of government and private funding, we are living the 1980s of the electronic industry, when the first merchant foundries were established. Soon, we will see more and more merchant foundries proposing well-established electronic design tools, product development kits, and mature component libraries. The open access journal Micromachines invites the submission of manuscripts in the developing area of silicon photonics. The goal of this Special Issue is to highlight the recent developments in this cutting-edge technology.]