Highly stable picosecond YAG:Nd3+ laser with a negative feedback

A picosecond YAG:Nd³⁺ laser with passive mode locking and a negative feedback loop was constructed. Trains of between 7 and 5000 pulses of 20 ps duration were generated. Theoretical and experimental analyses of the operation of a solid-state picosecond laser with a negative feedback loop were made treating this laser as a discrete object of control. The theory made it possible to describe completely operation of the investigated laser. A laser with a negative feedback loop was found to behave in a complex manner and, under certain conditions, it demonstrated chaotic behavior. The criteria of stability of the operation of picosecond lasers with a negative feedback loop were established.