A balanced cross correlator, the optical equivalent of a balanced microwave phase detector, is demonstrated. Its use in synchronizing an octave-spanning Ti:sapphire laser and a 30-fs Cr:forsterite laser yields 300-attosecond timing jitter measured from 10 mHz to 2.3 MHz. The spectral overlap between the two lasers is strong enough to permit direct detection of the difference in carrier-envelope offset frequency between the two lasers.
© 2003 Optical Society of America
[Optical Society of America ]
T. R. Schibli, J. Kim, O. Kuzucu, J. T. Gopinath, S. N. Tandon, G. S. Petrich, L. A. Kolodziejski, J. G. Fujimoto, E. P. Ippen, and F. X. Kaertner, "Attosecond active synchronization of passively mode-locked lasers by balanced cross correlation," Opt. Lett. 28, 947-949 (2003)