Genetic-algorithm-based method to optimize spatial profile utilizing characteristics of electrostatic actuator deformable mirror

• DOI: 10.1007/s10043-008-0025-9
• Publication Date: 2008-06-04T05:57:17Z
• Authors: Futoshi Matsui; Shin’ichi Goriki; Yukio Shimizu; Hiromitsu Tomizawa; Sakae Kawato; Takao Kobayashi
• Keywords: 01 natural sciences; 0104 chemical sciences

Arbitrary spatial beam shaping was demonstrated with a membrane electrostatic actuator type deformable mirror (DM). An automatic closed loop system must optimize such beam shapes as flattop. Well-characterized short pulse laser beam is widely required for a photocathode RF gun or for microscopic processing, etc. We propose a new sophisticated optimizing method based on a genetic algorithm (GA) for spatial shaping. A membrane type DM is driven by electrostatic attraction power, and applied electrode voltages vs displacement of membrane surface have a square function relationship. We prepare discrete electrode voltages to linearly change displacement as a utilized gene of the initial population in GA. Using uniform crossover without mutation in this method, we can make an arbitrary spatial beam shape quasi-flattop.