Carrier-envelope phase stabilization of modelocked lasers
We present advances in carrier-envelope phase stabilization of mode-locked lasers within the scope of both optical frequency metrology and ultrafast science. By drawing on the techniques of single-frequency laser stabilization and on improvements of ultrafast lasers, phase stabilization of Ti:sapphire (Ti:S) lasers has led to great advances in both the fields of optical frequency metrology and ultrafast phenomena [13]. In the former, it has resulted in the realization of an all optical atomic clock [5, 19] and in the latter it has allowed for waveform synthesis of ultrashort (similar to 2 cycle) pulses [14]. In this paper, we report on both development of the technology of and experimental results for modelocked laser stabilization. Phase coherence measurements to characterize various noise sources that lead to contamination of the carrier-envelope phase are discussed. Using this highly phase stable laser, we discuss a lock-in based technique to measure phase fluctuations and extra-cavity changes in the carrier-envelope phase due to propagation through a dispersive material. We also present an octave spanning Ti:S laser, which allows for carrier-envelope phase stabilization without the use of external broadening in fiber.