Fig. 2: Time evolution of the ISRS signal.
From: Transient measurement of phononic states with covariance-based stochastic spectroscopy
a ρc (ωIN, ωOUT) and b <ρc(ωR)> for selected values of the time delay Δt, showing the sign evolution of the vibrational signal. c Pseudo-colormap of <ρc (ωR, Δt)>. d 2D ISRS spectrum, achieved by Hilbert and Fourier transforms of <ρc (ωR, Δt)> as a function of ωR and Δt, respectively. Vertical (horizontal) dashed lines in b (c, d) indicate the frequency of known Raman modes of quartz.
