Direct imaging of Earth-like planets requires techniques and instruments for light suppression, such as wavefront control and coronagraphs, with precision that can only be achieved through the use of deformable mirrors. For space-based applications, deformable mirrors (DM) are used to correct for slowly time varying aberrations from thermal misalignments, but require very high accuracy, stability, low power consumption and low mass.

A major problem with current high-actuator-count DM drivers is the number of connections and cables, in addition to the mass of the electronics. The cables are arranged in bundles, which are expensive to manufacture and have considerable mass and complexity. They are also burdensome to install and deinstall adding complexity and cost to a project.

Microscale has created an Application-Specific Integrated Circuit (ASIC) designed to control the DMs will vastly reduce the mass of the electronics and reduces the number of required wires by two orders of magnitude.

Prototype ASIC & DM

An early prototype ASIC/DM that aims to solve the cabling/connector challenge.

This integrated ASIC-DM is ideal for space missions, where it offers significant reduction in mass, power and complexity, with performance compatible for high-contrast observations of exoplanets. In addition, only a few wires will connect it to the control computer greatly simplifying integration, reducing costs and increasing reliability. In future developments, it can be applied to other different DM formats while improving reliability. These ASICs can also be used with active primary mirrors such as the Active Hybrid Mirrors or the Active Shell Mirrors. Both of these mirror concepts use segmented primary mirrors with each segment having dozens of actuators. These technologies are under consideration for the generation flagship missions: LUVOIR and Far Infrared Surveyor. ASICs bonded to each segment would eliminate many cables and electronics packaging, leading to a lighter primary segment. This addresses a priority 1 technology gap in the 2016 Cosmic Origins technology report.

Working with Microscale, the JPL AO group is characterizing the performance of these DMs and ASICs.

16x16 DM
A 16x16 actuator Deformable Mirror (without an ASIC).

32x32 DM
A 32x32 assembled stack actuator array without face-sheet


Testing and Characterization of Deformable Mirrors
Lewis C. Roberts; Camilo Mejia Prada; J. Chris Shelton; Seth R. Meeker; Li Yao; Yuqian Wu; Xingtao Wu
Proceedings of SPIE, vol. 10703 , 1070375 (2018)
Copyright 2018 Society of Photo Optical Instrumentation Engineers https://doi.org/10.1117/12.2314296

Characterization of Low Mass Deformable Mirrors and ASIC drivers for High-Contrast Imaging
Camilo Mejia Prada, Li Yao, Yuqian Wu, Lewis C. Roberts, Jr., Chris Shelton, and Xingtao Wu
Proceedings of SPIE, vol. 10400, 1040011 (2017)
Copyright 2017 Society of Photo Optical Instrumentation Engineers http://dx.doi.org/10.1117/12.2271500

Driver ASICS for Deformable Mirrors
Xingtao Wu, Lewis C. Roberts, Jean Shelton, Yuqian Wu, and Li Yao
OSA Technical Digest, paper AOTh2C (2015)
Paper Link