Evolution of modelocked pulses and their application to timeresolved spectroscopy
Abstract
The transient buildup of the steady state transform limited, mode locked pulse from noise is studied for an actively mode locked laser whose atomic line is homogenously broadened. A simple model of a circulating, gaussian wave packet evolving from a single oscillatory axial mode exactly at atomic line center is developed. Axial mode coupling by the modulator creates phase and amplitude coherence among the modes, while the bandwidth of the Qswitched pulse is narrowed by the finite atomic linewidth. Two different approaches for treating this problem are discussed. The first assumes each axial mode to acquire modulation sidebands independently, broadening into a modelocked spectral packet, and an alternative treatment expands the field as a statistical superposition of the HermiteGaussian eigenmodes. Both these treatments agree with the simple model in their predictions for the pulsewidth.
 Publication:

Ph.D. Thesis
 Pub Date:
 1975
 Bibcode:
 1975PhDT........33P
 Keywords:

 Laser Mode Locking;
 Optical Emission Spectroscopy;
 Pulsed Lasers;
 Neodymium;
 Pulse Generators;
 Q Switched Lasers;
 Spatial Filtering;
 Yag Lasers;
 Lasers and Masers