Novel correlation spectroscopy measurements through femtosecond pulse induced supercontinuum generation

In the femtosecond pulse induced supercontinuum generation process, there is pulse splitting beyond a certain incident intensity. These split pulses show mutual coherence resulting in spectral interference. As the amount of pulse splitting increases with the amount of incident laser power, the interference is eventually washed out at high enough powers. We present distinctly structured interferometric features in femtosecond supercontinuum generation with incident laser powers, which are near threshold for supercontinuum generation. We argue that near threshold, these structures arise from the coherent superposition of pulses that are split initially into two daughter pulses during the supercontinuum generation process. An increase in the input pulse energy results in generating multiple daughter fragments in the temporal domain, which eventually reaches an extent that correlated interference structures are not measurable. Properties of the split pulse are different in different supercontinuum generation media as their propagation characteristics change given the different environments. This can be of immense use and application in spectroscopic applications and in coherence correlation measurements.