Performance of Large-Format Deformable Mirrors Constructed with TNO Variable Reluctance Actuators

TL;DR

This paper evaluates a new low-power variable-reluctance actuator for large deformable mirrors, demonstrating high linearity, low hysteresis, and promising performance metrics suitable for adaptive optics applications.

Contribution

The paper introduces a novel variable-reluctance actuator with significantly reduced power consumption and presents performance data of a large-format deformable mirror using this technology.

Findings

Linearity of 99.4% over 10 microns stroke

Hysteresis of 2.10% indicating precise control

Potential for use in adaptive secondary mirrors

Abstract

Advancements in making high-efficiency actuators are an enabling technology for building the next generation of large-format deformable mirrors. The Netherlands Organization for Applied Scientific Research (TNO) has developed a new style of variable-reluctance actuator that requires approximately eighty times less power to operate as compared to the traditional style of voice-coil actuators. We present the performance results from laboratory testing of TNO's 57-actuator large-format deformable mirror from measuring the influence functions, linearity, hysteresis, natural shape flattening, actuator cross-coupling, creep, repeatability, and actuator lifetime. We measure a linearity of 99.4 +- 0.33% and hysteresis of 2.10 +- 0.23% over a stroke of 10 microns, indicating that this technology has strong potential for use in on-sky adaptive secondary mirrors (ASMs). We summarize plans for future lab prototypes and ASMs that will further demonstrate this technology.