Passive mode locking in dye lasers with different resonator configurations

A study was made of the relationship between the pulse duration, on the one hand, and the nature of self-modulation of the amplification and absorption (which occurs in a dye laser resonator in the case of passive mode locking), on the other. A formula was obtained for relating the energy density of a pulse in the active medium to the gain G encountered by the pulse in the round trip through the resonator. The main parameters governing the duration of the output pulses were the energy density of a pulse in an amplifier or an absorber and the ratio of their characteristic saturation energies. A pulse duration of 200 fsec was achieved without compensation of phase modulation.