Performance of Large-Format Deformable Mirrors Constructed with Hybrid Variable Reluctance Actuators II: Initial Lab Results from FLASH

TL;DR

This paper reports initial laboratory results of a large-format deformable mirror using innovative hybrid variable reluctance actuators that are significantly more power-efficient, demonstrating promising performance metrics for adaptive optics applications.

Contribution

The study introduces a new hybrid variable reluctance actuator design and presents initial performance data of a 19-actuator deformable mirror, highlighting its potential for adaptive secondary mirrors.

Findings

Low power consumption compared to traditional actuators

Good linearity and minimal hysteresis observed

Fast dynamic response suitable for high-contrast imaging

Abstract

Advancements in high-efficiency hybrid variable reluctance (HVR) actuators are an enabling technology for building the next generation of large-format deformable mirrors, including adaptive secondary mirrors. The Netherlands Organization for Applied Scientific Research (TNO) has developed a new style of hybrid variable reluctance actuator that requires approximately seventy-five times less power to operate as compared to the traditional style of voice-coil actuators. We present the initial performance results from laboratory testing of TNO's latest 19-actuator prototype deformable mirror, FLASH. We report the actuator cross-coupling, linearity, hysteresis, natural shape flattening, and drift as measured with a Zygo interferometer and a set of four capacitive sensors. We also present results of the dynamic performance of the FLASH on sub-millisecond timescales to estimate the limits of this technology for high-contrast imaging adaptive optics. We confirm that this technology has strong potential for use in on-sky adaptive secondary mirrors without the need for active cooling.