Carrier-envelope phase stabilization of femtosecond modelocked lasers and direct optical frequency synthesis

Summary form only given. Progress in femtosecond pulse generation has made it possible to generate optical pulses that are only a few cycles in duration. This has resulted in rapidly growing interest in controlling the phase of the underlying carrier wave with respect to the envelope. The carrier-envelope phase is normally not important in optics; however, for such ultrafast pulses it can have physical consequences. Concurrently, modelocked lasers, which generate trains of ultrashort pulses, have become an important tool in optical frequency measurement. There is a close connection between these two apparently disparate topics. We have exploited this connection to develop a frequency domain technique that stabilizes the carrier phase with respect to the pulse envelope. Using the same technique, we performed absolute optical frequency measurements using a single modelocked laser with the only input being a stable microwave clock.