Next-generation deformable mirror electronics

Abstract

Full-custom electronics have been designed to drive Xinetics deformable mirrors, for use with the PYRAMIR (Calar Alto) and LINC/NIRVANA (Large Binocular Telescope) AO instruments, under contract to the Max-Planck-Institut fur Astronomie (MPIA). Significant enhancements to the original 1998 design for ALFA (Calar Alto) have been incorporated, including an embedded 2.1 Gb/s fiber link, temperature-controlled bias voltage, and multiple tip-tilt control outputs. Each 7U chassis with integral power supplies can drive mirrors of up to 349 actuators, and may be cascaded to support larger mirrors. A customized 600 MHz 'C6415 DSP module was specified to minimize latency, with frame rates above 7.5 KHz demonstrated for the 349-actuator DM. Power op-amps with 0.38 W/channel quiescent dissipation were chosen to reduce heat load, while supporting full-power (60 Vpp) bandwidth to above 300 Hz. These subsystems were successfully integrated in Heidelberg during November, 2003. The engineering firm responsible for the design, Cambridge Innovations, has since been awarded two additional contracts for DM electronics, including a new full-custom design for AURA (Gemini Observatory) to drive multiple high-voltage CILAS piezo bimorph DMs.