Studying Ultrafast Molecular Dynamics in Pump-Probe Experiments with Femtosecond Lasers
Joey Harrington
Fort Hays State University
Physics Major
Mentored by Dr. Daniel Rolles and Artem Rudenko
This summer, I was given the opportunity to work in Dr. Rolles and Dr. Rudenko's AMO groups. I started off the summer getting to do some alignment with the laser. I was allowed to tune several of the mirrors to try and reach optimal spatial overlap of our 266 nm UV pulse and our 800 nm IR probe.
Figure 1: General construction of our optical setup for our laser.
After I finished that, I began doing some data analysis of the molecules we were looking at. The main molecule that my work was focused on was cyclohexadiene. I was able to generate some spectra that showed the yield of each fragment versus the time of flight.
Figure 2: Spectra containing the yield as a function of the time of flight.
I was also fortunate to have Kurtis's help getting graphs that show the spectra of position versus the time of flight of the observed fragments.
Figure 3: X-position as a function of the time of flight.
Figure 4: Y-position as a function of the time of flight.
Towards the end of the program I was starting to look into the yield of each individual fragment versus the delay between our UV and IR pulses.
Figure 5: Yield of each fragment as a function of delay.
Finally, I ended the program with the choice of either doing more optical alignment or more data analysis. I opted for the optical alignment. I was unable to get any FROG traces from our current setup.
Acknowledgments
I would like to thank Daniel, Artem, Kurtis, and Farzaneh for allowing me to observe, understand, and learn the research process. Kurtis was very helpful throughout the whole process. I am glad he was so patient with me. Also, I want to thank the NSF for funding this research opportunity. Finally, the other REU students for making the time here memorable.