Cavity-length stabilization technique for synchronously pumped mode-locked lasers

We demonstrate a technique for active stabilization of the cavity length of synchronously pumped mode-locked lasers. The technique is general and relies on the ultrashort-pulse forming process itself. It can be implemented in a variety of nonparasitic ways, has high sensitivity to changes in true optical path length of the cavity, and offers the possiblity of long-term stabilization.