Fig. 3: Coherent Phonon Spectra Reveal the Dominant TO mode.
From: Coupling of electronic transition to ferroelectric order in a 2D semiconductor
a, b Transient reflectivity spectra of NbOI2 measured at RT for probe polarization parallel to c- (a) or b-axis (b). The color bar indicates the magnitude of ΔR/R0. c FT of the oscillatory components extracted from (a, b) at off-resonant probe region (1.55 eV). d FT of the oscillator components extracted from (a, b) at resonant probe region (2.30 eV).
