Abstract

The coherence of optical materials can be excited when Rabi frequency is grater than absorption line width i.e. ω_R>ω_a. In solid-state materials or organic dye solutions at room temperature, however, absorption bands have tens of THz and femtosecond dephasing time, so intense, quick and broadband excitation is required for their coherence control. In this paper, we have demonstrated absorption and emission control in the ultra-fast media by optical phase of broadband pump beams. An intense femtosecond supercontinuum generated in rare gas was used as the pump source. The phase sensitive coherent excitation was carried out by coaxial two pulse (like as white light interference) pumping scheme. The correlation time of the pump beams with a 300-800 nm spectral window of the apparatus was measured to be 1.4 fs corresponding to monocycle temporal resolution. The phase dependent absorptions and emissions were measured by a third beam (weak and off-axis white-light probe) as a function of optical delay between the two pump pulses.

© 2000 IEEE