Femtosecond difference transmission and difference phase spectra measured by frequency domain interferometer

Abstract

The pump-probe spectroscopy with a white-light continuum pulse has been playing major roles in femtosecond absorption spectroscopy because difference transmission spectra (DTS) can be obtained by using a multichannel spectrometer without scanning a probe wavelength. On the other hand, femtosecond phase spectroscopy, which is complementary to femtosecond absorption spectroscopy, is still in the primitive stage. This is mainly because there have been no methods by which difference phase spectra (DPS) can be obtained with a multichannel spectrometer as in the case of DTS.