Weight Calibration: this study looks at how the thermal-compensation system should be tuned as the laser beam moves off-center on a detector mirror, with a fixed point-absorber defect in place. The optimizer that sets the actuator powers tries to flatten the wavefront, and it balances two kinds of distortion( i.e. surface distortion against substrate optical-path distortion) by a ratio that had been fixed at 20:1, but that value was only validated for a centered beam. So here I sweeps this ratio across beam positions from 0–5 cm along +x, with and without the absorber, re-optimizing the actuator powers at each position and judging each choice by the resulting power recycling gain from the fully locked interferometer.

Slides