Picosecond laser system continuously tunable in the 0.6-4-microm range

A continuously tunable picosecond laser system has been developed that operates in two modes: cw (100 MHz) and pulsed (10 Hz). In either mode the tuning range is approximately the same: from 0.6-4 microm. The pulse duration can also be selected: either short (typically 5 ps) or long (typically 50 ps) pulses are available. The average output power is in the milliwatt range for both repetition rates. In addition, both modes of operation are simultaneously available, and they are mutually synchronized. The system is based on a mode locked high power Nd:YLF laser which synchronously pumps a dye laser and seeds a Nd:YLF regenerative amplifier. Frequency mixing and parametric generation/amplification in KTiOPO(4) are used to obtain the large tunability.