Picosecond duration laser pulse generation by simultaneous active-passive mode-locking in Ar+ ion and dye lasers

We use a rate equation model to analyse a technique for the generation of picosecond duration laser pulses in argon pumped dye lasers. The system is based on passive mode-locking of the Ar⁺ laser by saturable absorption of the dye which is inserted in the Ar⁺ laser cavity. Simultaneously, the dye is forced to oscillate in a regime of synchronously pumped mode-locking. The system is relatively simple, does not require the use of an acousto-optical light modulator and can be easily implemented in commercially available lasers. Pulses shorter than 100 ps and having an average power of 20 mW were obtained at a repetition rate of 110 MHz. Good agreement between the model and experimental results was also obtained.