Photonic Systems Brown Bag Seminar

Thursday, April 7, 2005, at 12 noon                                RLE Haus Room, 36-428

Towards multi-GHz integrated femtosecond laser systems

Felix J. Grawert

Integrated and very high repetition rate mode-locked lasers offer
tremendous potential for future optical data communication systems, in
high-speed sampling and in low-noise frequency standards. However, to date
their realization was prevented by Q-switching instabilities. We present a
complete analysis of the laser dynamics from a control systems viewpoint
and show theoretically and experimentally that different approaches to
laser stabilization can overcome this limitation, opening the path to
higher repetition rates and therefore also to integration. Furthermore,
compact laser systems require monolithic integration of gain medium and the
nonlinear semiconductor element, which is responsible for pulse generation.
For the first time, we were able to fabricate such a device in the
Silicon-Germanium material system, that is compatible to Er-doped glass, a
common gain medium used in optical communications devices. With our work on
both laser dynamics and material aspects we are addressing the challenge of
fabricating compact, highly integrated and inexpensive mode-locked
femtosecond lasers.