Cross-polarized femtosecond stimulated Raman scattering spectroscopy

We present a method to retrieve the spectral intensity and phase of a Raman resonance over a broad spectral range. In coherent Raman scattering, the Raman transition is stimulated by two light waves (pump and probe) with a difference frequency matching the resonance. Common methods like stimulated Raman scattering (SRS) or Raman-induced Kerr effect spectroscopy (RIKES, [1]) measure the Raman intensity spectrum by scanning the difference frequency of two narrow bandwidth pulses across the region of interest. Techniques like optical heterodyne-detected RIKES [2] or the recently developed balanced-detection RIKES [3] additionally grant access to the phase, but still, the pulses need to be scanned in frequency. In femtosecond SRS (FSRS, [4]) or broadband RIKES [5], a wide intensity spectrum is measured by employing a broadband probe pulse.