Abstract

We present a semiclassical model for a synchronously pumped mode-locked dye laser with a saturable absorber included in the cavity. This combination, called a hybridly mode-locked system, has the advantage of producing stable picosecond and subpicosecond pulses for long periods of operation. The particular system of interest is the practically realized rhodamine 6G laser with either DODCI or DQOCI as the saturable absorber. Our model may be solved numerically, and our computed results are presented in terms of the pulse autocorrelations, which are the parameters usually obtained in our experiments and in similar studies elsewhere. In addition to accounting for the finite coherence times of both dyes, our model also includes molecular orientation effects which reduce the efficiencies of the interactions. A key parameter of our model is the length mismatch between the dye laser and pump laser. The effect of this length detuning on the output pulse character is discussed. The pulse shaping and shortening caused by the saturable absorber are also emphasized.

© 1988 Optical Society of America