title: Active correction of thermal lensing through external radiative thermal actuation.
abstract: Absorption of laser beam power in optical elements induces thermal gradients that may cause unwanted phase aberrations. In precision measurement applications, such as laser interferometric gravitational-wave detection, corrective measures that require mechanical contact with or attachments to the optics are precluded by noise considerations. We describe a radiative thermal corrector that can counteract thermal lensing and (or) thermoelastic deformation induced by coating and substrate absorption of collimated Gaussian beams. This radiative system can correct anticipated distortions to a high accuracy, at the cost of an increase in the average temperature of the optic. A quantitative analysis and parameter optimization is supported by results from a simplified proof-of-principle experiment, demonstrating the method's feasibility for our intended application.
authors.affiliation: Department of Physics, Massachusetts Institute of Technology, 175 Albany Street, Cambridge, Massachusetts 02139, USA. rclawren@mit.edu
authors.forename: Ryan
authors.initials: R
authors.lastname: Lawrence
authors.forename: David
authors.initials: D
authors.lastname: Ottaway
authors.forename: Michael
authors.initials: M
authors.lastname: Zucker
authors.forename: Peter
authors.initials: P
authors.lastname: Fritschel