Developing Adaptive Secondary Mirror Concepts for the APF and W.M. Keck Observatory Based on HVR Technology

TL;DR

This paper explores the development of adaptive secondary mirrors using hybrid variable reluctance technology to enhance adaptive optics in telescopes like APF and Keck, aiming for improved performance and flexibility.

Contribution

It introduces a novel application of HVR actuator technology for adaptive secondary mirrors and presents conceptual designs for telescopes including APF and Keck.

Findings

HVR-based ASMs can be stiffer and more power-efficient.

Designs for ASMs at APF and Keck are developed.

Potential to double light throughput and improve image stability.

Abstract

An Adaptive secondary mirror (ASM) allows for the integration of adaptive optics (AO) into the telescope itself. Adaptive secondary mirrors, based on hybrid variable reluctance (HVR) actuator technology, developed by TNO, provide a promising path to telescope-integrated AO. HVR actuators have the advantage of allowing mirrors that are stiffer, more power efficient, and potentially less complex than similar, voice-coil based ASM's. We are exploring the application of this technology via a laboratory testbed that will validate the technical approach. In parallel, we are developing conceptual designs for ASMs at several telescopes including the Automated Planet Finder Telescope (APF) and for Keck Observatory. An ASM for APF has the potential to double the light through the slit for radial velocity measurements, and dramatically improved the image stability. An ASM for WMKO enables ground layer AO correction and lower background infrared AO observations, and provides for more flexible deployment of instruments via the ability to adjust the location of the Cassegrain focus.