Abstract

This paper describes auto-aligned femtosecond lasers controlled by genetic algorithms (GAs) Femtosecond lasers have been developed rapidly and generation of sub 10-fs pulses has been achieved by Kerr lens mode-locking. However, for femtosecond lasers, it is necessary to consider the nonlinear effect because the nonlinearity in the cavity is enhanced as the peak power increases. Therefore, we should optimize the alignment such as focus of concave mirrors if we change the pump power For compensation of such nonlinearlity in laser cavity, we have proposed and established an auto-aligned laser system based on GA [1]. GA is a robust search algorithm which uses multiple chromosomes and apply natural seleciton-like operations to them in seeking improved solutions [2]. We made the system based on precise and compact positioning actuators with pm resolution. The initial experiments for CW oscillation for a Ti:sapphire laser obtained 1.66 times higher output power with 3 hours, compared to a hill-top-climbing method which corresponds to manual alignment procedure [1] This laser system has three advantages in potential, namely; (1) higher power, (2) automatic and reliable alignment and (3) compactness.

© 2000 IEEE