The effects of ground-state dynamics on the emission spectra of electric-discharge-pumped XeCl lasers: A model for injection locking
Abstract
The bandwidth of excimer lasers is typically 1-10 Å as a result of their transitions being multiline or bound-free. To obtain high power with narrow bandwidth injection locking is usually required. In this paper, we investigate the spectral characteristics of electric-discharge-pumped XeCl (B→X) lasers during injection locking and free-running operation. This study is performed using results from an electron kinetics and plasma chemistry model for Ne/Xe/HCl/H2 mixtures which includes multiline laser extraction. We find that the experimentally observed lasing spectrum cannot be explained if a thermal distribution is used for the vibrational levels of the X state. Therefore, the vibrational levels of the B, C, and X states are explicitly included in the model and the gain spectrum is computed using Franck-Condon factors. Results from the model indicate that bottlenecking occurs on the v'=0→v`=1 transition, while the dissociation rate for XeCl(X,v`=2) is faster than the removal rate for XeCl(X,v`=1). Injection locking characteristics are examined as a function of injection intensity and small-signal gain. Due to nonequilibrium dynamics in the ground state, locking efficiency does not necessarily increase with increasing small-signal gain.
- Publication:
-
Journal of Applied Physics
- Pub Date:
- June 1989
- DOI:
- 10.1063/1.343319
- Bibcode:
- 1989JAP....65.4138O
- Keywords:
-
- Electric Discharges;
- Emission Spectra;
- Ground State;
- Injection Locking;
- Laser Outputs;
- Xenon Chloride Lasers;
- Excimer Lasers;
- Franck-Condon Principle;
- Gas Mixtures;
- Power Gain;
- Lasers and Masers