A noninvasive pulse-tracking technique has been exploited to observe the time-resolved motion of an ultrashort light pulse within an integrated optical microresonator. We follow a pulse as it completes several round trips in the resonator, directly mapping the resonator modes in space and time. Our time-dependent and phase-sensitive measurement provides direct access to the angular group and phase velocity of the modes in the resonator. From the measurement the coupling constants between the access waveguides and the resonator are retrieved while at the same time the loss mechanisms throughout the structure are directly visualized.
© 2004 Optical Society of America
(120.3180) Instrumentation, measurement, and metrology : Interferometry
(170.5810) Medical optics and biotechnology : Scanning microscopy
(170.6920) Medical optics and biotechnology : Time-resolved imaging
(250.5530) Optoelectronics : Pulse propagation and temporal solitons
(320.2250) Ultrafast optics : Femtosecond phenomena
H. Gersen, D. J. W. Klunder, J. P. Korterik, A. Driessen, N. F. van Hulst, and L. Kuipers, "Propagation of a femtosecond pulse in a microresonator visualized in time," Opt. Lett. 29, 1291-1293 (2004)