Adaptive correction of a tightly focused, high-intensity laser beam by use of a third-harmonic signal generated at an interface.
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.
Planchon
T A
TA
Colorado School of Mines, Golden 80401, USA. tplancho@mines.edu
Amir
W
W
Field
J J
JJ
Durfee
C G
CG
Squier
J A
JA
Rousseau
P
P
Albert
O
O
Mourou
G
G