Numerical analysis of pulse generation in synchronously mode-locked cw dye lasers

We present theoretical results on the characteristics of pulses generated by a synchronously pumped dye laser. Our analysis indicates the important influence of spontaneous emission on shape and frequency chirp of the pulse. Dye-laser operation is possible within a wide range of cavity mismatch. A large mismatch of the lengths of the dye and the pump-laser cavity results in the generation of noise bursts caused by the influence of spontaneous emission. At small cavity mismatch pulse profile and frequency chirp of the pulse are directly generated in the steady-state regime by algebraic equations. Our formulas indicate that the sign of the pulse chirp depends only on the sign of the shift between laser frequency and centre frequency of the amplifying transition.