Femtosecond Laser Spectroscopy, Autocorrelation, and Second Harmonic Generation: An Experiment for Undergraduate Students

With the increase in integrated photonics careers, it is essential that students in undergraduate institutions gain experience with equipment, techniques, and ideas used in the field.  In this paper, an upper level undergraduate lab is designed utilizing a KMLabs Collegiate^TM Ti:Sapphire oscillator kit in combination with a nonlinear crystal, beta-barium borate (BBO).  Students apply autocorrelation techniques to study the pulse width of the Collegiate laser pulses, using the max Second Harmonic Generation (SHG) signal from the BBO crystal as the “0” for the autocorrelation.  With the ease, simplicity, and durability of the KMLabs Collegiate oscillator kit, students not only gain experience in using autocorrelation to study laser pulses, but also learn about the inner workings of femtosecond laser systems and begin to understand the basics of SHG, dispersion, and its applications.