Evolution of mode-locked pulses and their application to time-resolved spectroscopy
Abstract
The transient build-up 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 Q-switched 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 mode-locked spectral packet, and an alternative treatment expands the field as a statistical superposition of the Hermite-Gaussian 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