Tunable subnanosecond pulse generation in a ring dye laser bi-directionally pumped by overlapped nanosecond pulses

We report an original approach for tunable subnanosecond pulse (200-500 ps) generation in a ring dye laser. It is based on limitation of generation to a single "spike" from the starting transient process using for excitation a quasi-rectangular pulse with duration less or comparable with the time interval between the spikes. The pumping pulse (3-7 ns) is formedboth by electrooptical division of a standard nanosecond (15-50 ns) pulse emitted by a Q-modulated laser in an original scheme and by overlapping of the obtained partial pulses which are fed bi-directionally into the active medium of the ring laser.