Building a GRAVITY+ Adaptive Optics Test Bench

TL;DR

This paper describes the design and implementation of a compact, cost-effective test bench for integrating and testing the GRAVITY+ adaptive optics system, simulating telescope and room environments.

Contribution

It introduces a novel, low-cost, compact test bench that enables independent alignment and integration of the GRAVITY+ adaptive optics components.

Findings

Successfully designed a compact test bench within 20 sqm.

Implemented solutions for low-cost and independent alignment.

Facilitated integration of the GPAO wavefront sensor.

Abstract

We present the testbench aimed at integrating the GRAVITY+ adaptive optics GPAO. It consists of two independent elements, one reproducing the Coud{\'e} focus of the telescope, including the telescope deformable mirror mount (with its surface facing down), and one reproducing the Coud{\'e} room opto-mechanical environment, including a downwards-propagating beam, and the telescope mechanical interfaces in order to fit in the new GPAO wavefront sensor. We discuss in this paper the design of this bench and the solutions we adopted to keep the cost low, keep the design compact (allowing it to be fully contained in a 20 sqm clean room), and align the bench independently from the adaptive optics. We also discuss the features we have set in this bench.