Related Experiment Video
Updated: Jun 11, 2026

Bringing the Visible Universe into Focus with Robo-AO
Published on: February 12, 2013
Linearization of the response of a 91-actuator magnetic liquid deformable mirror
Denis Brousseau1, Ermanno F Borra, Maxime Rochette
1Département de physique, de génie physique et d'optique and Centre d'optique, photonique et laser (COPL), Université Laval, 2375 rue de la Terrasse, Québec, Québec,G1V 0A6 Canada. denis.brousseau@copl.ulaval.ca
Abstract:
We present the experimental performance of a 91-actuator deformable mirror made of a magnetic liquid (ferrofluid) using a new technique that linearizes the response of the mirror by superposing a uniform magnetic field to the one produced by the actuators. We demonstrate linear driving of the mirror using influence functions, measured with a Fizeau interferometer, by producing the first 36 Zernikes polynomials. Based on our measurements, we predict achievable mean PV wavefront amplitudes of up to 30 microm having RMS residuals of lambda/10 at 632.8 nm. Linear combination of Zernikes and over-time repeatability are also demonstrated.
Related Concept Videos
Linear Approximation in Time Domain
For a simple pendulum with a mass evenly distributed along its length and the center of mass located at half the pendulum's length, the...
Mechanical Systems

