SRAO: optical design and the dual-knife-edge WFS

TL;DR

SRAO is a new adaptive optics system for the SOAR telescope that uses a cost-effective dual-knife-edge wavefront sensor to enable high-resolution imaging of thousands of targets annually, aiding exoplanet research.

Contribution

Introduction of the SRAO instrument with a novel dual-knife-edge wavefront sensor, reducing costs while maintaining high wavefront error sensitivity for southern-hemisphere observations.

Findings

Capable of guiding on targets down to V=16 with diffraction-limited NIR imaging.

Can observe hundreds of targets per night through automation.

Provides a cost-effective alternative to pyramid sensors with similar performance.

Abstract

The Southern Robotic Adaptive Optics (SRAO) instrument will bring the proven high-efficiency capabilities of Robo-AO to the Southern-Hemisphere, providing the unique capability to image with high-angular-resolution thousands of targets per year across the entire sky. Deployed on the modern 4.1m SOAR telescope located on Cerro Tololo, the NGS-AO system will use an innovative dual-knife-edge wavefront sensor, similar to a pyramid sensor, to enable guiding on targets down to V=16 with diffraction limited resolution in the NIR. The dual-knife-edge wavefront sensor can be up to two orders of magnitude less costly than custom glass pyramids, with similar wavefront error sensitivity and minimal chromatic aberrations. SRAO is capable of observing hundreds of targets a night through automation, allowing confirmation and characterization of the large number of exoplanets produced by current and future missions.