Progress in high average power ultrafast lasers

The impact of femtosecond lasers across science and engineering has been significant. The one area which has so far proved hard to access for femtosecond lasers has been the combination of high peak power and high average power. This review seeks to highlight the issues which make high average power hard to achieve in many femtosecond systems, and looks at the routes that are now being taken to achieve the goal of high peak and high average power