1. Development of a High-Sensitivity Pump-Probe Fast Scanning Delay Line
Stephanie Majewski
University of Urbana-Champaign
University of Florida
Faculty Mentor: Professor David Reitze

2. Introduction Femtosecond “LASER”s Pump-Probe Spectroscopy
Lock-in Method
Fast-Scan System

4. Femtosecond Lasers
1 fs = s

5. What Happens in 100 Femtoseconds?
Light Travels 30 μm
Electrons Collide With Electrons
Solids Begin to Melt Under Laser Irradiation
Chemicals Dissociate
There are about as many femtoseconds in a minute as there are minutes in the age of the universe.

8. Project Objectives Characterize Motion of Shaker Design Mirror Mount
Optimize Performance of Shaker- Mount System
Implement System in Pump-Probe Experiment

9. The “Shaker”

14. Mirror Mount

15. Obstacles ... Elliptical Beam Shape Unstable Mirror Mount
Wobble in Drive Arm of Shaker

16. Solutions!
Uniform Bolt Force on Mirror Yielded Circular Beam Shape, Mirror Rattle Minimized
Extra Screw Added Stability to Mount
Beam Jitter Corrected Optically

21. Time-Resolved Nanotube Transmission Measurement
Achieved successful fast-scan system implementation in pump-probe experiment
Measurement itself unsuccessful due to intrinsic scattering of sample
In future, can try using cross-polarization and other methods to reduce scattering.

22. Conclusion Developed Shaker Design for Fast Scanning System
Characterized Shaker Motion and Corrected Beam Jitter to Within Acceptable Limits
Implemented Shaker in Time-Resolved Carbon Nanotube Transmission Measurement

23. Acknowledgements Professor David Reitze Mark Moores and Anatoly Efimov
Drs. Kevin Ingersent and Alan Dorsey
NSF Research Experience for Undergraduates