title: Adaptive optics for direct laser writing with plasma emission aberration sensing.
abstract: Aberrations affect the focal spot quality in direct laser write applications when focusing through a refractive index mismatch. Closed loop adaptive optics can correct these aberrations if a suitable feedback signal can be found. Focusing an ultrafast laser beam into transparent dielectric material can lead to plasma formation in the focal region. We report using the supercontinuum emitted by such a plasma to measure the optical aberrations, the subsequent aberration correction using a spatial light modulator and the fabrication of nanostructures using the corrected optical system.
authors.affiliation: Department of Engineering Science, University of Oxford, Oxford, United Kingdom.
authors.forename: Alexander
authors.initials: A
authors.lastname: Jesacher
authors.forename: Graham D
authors.initials: GD
authors.lastname: Marshall
authors.forename: Tony
authors.initials: T
authors.lastname: Wilson
authors.forename: Martin J
authors.initials: MJ
authors.lastname: Booth
mesh_terms: D004867:Equipment Design; D019544:Equipment Failure Analysis; D006358:Hot Temperature; D007834:Lasers; D007909:Lenses; D049329:Nanostructures / Q000737:chemistry* / Q000528:radiation effects* / Q000648:ultrastructure; D055096:Optical Devices; D012031:Refractometry / Q000295:instrumentation*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013499:Surface Properties