MEMS Deformable Mirror Development for High-Contrast Imaging I: Miniaturized, Flight-Capable Control Electronics

Deformable mirrors (DMs) are a critical technology to enable coronagraphic direct imaging of exoplanets with current and future ground- and space-based telescopes as well as future mission concepts, such as the Habitable Exoplanet Observatory (HabEx) and the Large UV/Optical/IR Surveyor (LUVOIR). The latter concepts aim to image a diversity of exoplanet types ranging from gas giants to Earth analogs, which requires large actuator count, fine surface height resolution (10 pm), and driving electronics that are radiation resilient and have low mass and volume. In this paper, we present the design and testing of a flight-capable, miniaturized DM controller. We achieved contrasts on the order of 5×10−9 on a coronagraph test bed in a vacuum chamber in the High Contrast Imaging Testbed (HCIT) facility at NASA’s Jet Propulsion Laboratory (JPL) demonstrating that the electronics are capable of meeting the requirements of coronagraph instruments on future space telescopes. We also report on functionality testing on-board the high-altitude balloon experiment “Planetary Imaging Concept Testbed Using a Recoverable Experiment - Coronagraph (PICTURE-C),” which aims to directly image debris disks and exozodiacal dust around nearby stars. The controller is designed for the Boston Micromachines Corporation Kilo-DM and is readily scalable to larger DM formats. The three main components of the system (the DM, driving electronics, and mechanical and heat management) are designed to be compact and have low-power consumption to enable its use not only on exoplanet missions, but also in a wide-range of applications that require precision optical systems, such as direct line-of-sight laser communications. The controller is capable of handling 1,024 actuators with 220 V maximum dynamic range, 16-bit resolution,14-bit accuracy, and operating at up to 1kHz frequency. The system fits in a 10×10×5 cm3 volume, weighs less than 0.5 kg, and consumes less than 8 W. We have developed a turnkey solution reducing the risk for future missions, lowering their cost by significantly reducing volume, weight, and power consumption of the wavefront control hardware.