Studies of relaxation oscillations in organic dye lasers

The transient phenomena of relaxation oscillations and "initial spikes" in organic dye lasers are studied experimentally and theoretically. Both damped relaxation oscillations and initial spikes are clearly observed in N2laser-pumped dye lasers under appropriate conditions which are furthermore shown to agree with theoretical considerations. Linearized rate equations obtained with small-signal approximation are used to describe the initial-spiking phenomenon; for the more general phenomenon of relaxation oscillations computer solutions of the coupled rate equations are obtained. Comparisons with experimental observations show excellent qualitative agreement. Based on the results of these studies, a general technique using the idea of controlled resonator transients is described for tunable subnanosecond pulse generation from laser-pumped dye lasers in the near UV and the visible region of the spectrum.