Deformable mirror using magnetic membranes: application to adaptive optics in astrophysics

Abstract

An alternative approach to more compact deformable mirrors for adaptive optics is developed. A thin and flexible reflective membrane is coated with a magnetic layer and locally deformed by the field created by an array of planar microcoils. This novel technology should enable higher resolution with smaller, lighter integrated mirrors. Several complementary modelling tools are used to study the electromagnetic, mechanical, magneto-mechanical and thermal behaviour of the device. A first prototype of OE 30 mm mirror with a matrix of permanent magnets and an array of 25 microcoils is under construction

A review of active optical devices: II. Phase modulation

“…An array of small micromagnets is bonded to the underside of the membrane and the membrane is then mounted above an array of planar microcoils on a silicon substrate. The vertical actuation can be done in both the directions while only attraction is possible with the electrostatic one [92].…”

A Design Approach to Reducing Stress and Distortion Caused by Adhesive Assembly in Micromachined Deformable Mirrors

“…Many DMs have been produced by bonding piezoelectric actuators [11][12][13] or permanent magnets [14,15] to the face sheet. Various techniques and materials have been used to provide a reliable, stable, low-stress adhesive connection between components.…”

Non-contact Deformable Mirror Actuator for Spherical Aberration Compensation

“…One approach to realize a high reliable actuator was deforming a mirror without physical contact. [6][7][8][9] Electrostatic MEMS mirror actuators has a simple electrode configurations to deform the mirror. [6][7][8] However, those actuators required more than several tens of driving voltages for several micrometers of mirror deformation.…”

“…On the other hand, the electromagnetic MEMS mirror drove with several voltages for mirror deformations. 9) But the coils for generating the magnetic field was complicated.…”