Ultrafast Dynamics of IR125 and IR144 Using Femtosecond Coherence Spectroscopy

Ryan J. Debord, California State University, Chico


Transient absorption spectroscopy can resolve ultrafast dynamics that result from photo-initiated processes like photon absorption from a laser. Here we report on the construction of a transient absorption spectrometer and its use to investigate ultrafast dynamics of laser dyes IR-125 and IR-144. Laser dyes are common object of interest for ultrafast dynamics studies because of their use in the creation dye lasers and there application in biomedical fields. Ultrafast decay was observed. The, expected coherent oscillations were present but unclear in the transient absorption measurement due to signal noise(presumably from the sensor). Additionally, we found that our laser produces a secondary pulse roughly 700 to 1000fs after the primary pulse. The secondary pulse results in re-pumping of our sample which confuse our analysis of the oscillations.