Femtosecond time-resolved dispersion relations studied with a frequency-domain interferometer

Abstract
Difference phase and transmission spectra (DPS and DTS) due to induced phase modulation of probe pulses in CS2 were measured with a femtosecond frequency-domain interferometer. Signals that satisfy the Kramers-Kronig (KK) relations with opposite signs were observed. At zero time delay, DTS and DPS were both even functions with respect to the probe center frequency due to the fifth- and third-order nonlinearities, respectively. The conditions for applying the KK relations to time-resolved data were obtained theoretically and verified experimentally.