Dynamic Spatial Filtering of Deformable Mirror Commands For Mitigation of the Waffle Mode (Postprint)

摘要

The conventional adaptive-optics (AO) system configuration consisting of a Shack-Hartmann wavefront sensor using the Fried geometry is prone to an unsensed waffle mode because of an inability to have discrete point reconstruction of the phase at the actuator positions. Techniques that involve filtering and/or projecting out the waffle mode in the reconstructor have been shown to be effective at not allowing the unwanted mode to occur, but come at the cost of also omitting relevant high frequency content from the measured phase. This paper analyzes a technique of sensing the waffle mode in the deformable mirror commands and applying a spatial filter to these commands in order to mitigate for the waffle mode. Directly spatially filtering the deformable mirror commands gives the benefit of maintaining the reconstruction of high frequency phase of interest while having the ability to alleviate for the waffle pattern when it arises.