title: Adaptive correction of a tightly focused, high-intensity laser beam by use of a third-harmonic signal generated at an interface.
abstract: By using the third-harmonic signal generated at an air-dielectric interface, we demonstrate a novel way of correcting wavefront aberrations induced by high-numerical-aperture optics. The third harmonic is used as the input physical parameter of a genetic algorithm working in closed loop with a 37-actuator deformable mirror. This method is simple and reliable and can be used to correct aberrations of tightly focused beams, a regime where other methods have limitations. Improvement of the third-harmonic signal generated with an f/1.2 parabolic mirror by 1 order of magnitude is demonstrated.
authors.affiliation: Colorado School of Mines, Golden 80401, USA. tplancho@mines.edu
authors.forename: T A
authors.initials: TA
authors.lastname: Planchon
authors.forename: W
authors.initials: W
authors.lastname: Amir
authors.forename: J J
authors.initials: JJ
authors.lastname: Field
authors.forename: C G
authors.initials: CG
authors.lastname: Durfee
authors.forename: J A
authors.initials: JA
authors.lastname: Squier
authors.forename: P
authors.initials: P
authors.lastname: Rousseau
authors.forename: O
authors.initials: O
authors.lastname: Albert
authors.forename: G
authors.initials: G
authors.lastname: Mourou