Mateen, Mala (AFRL), Codona, Johanan (University of Arizona), Guyon, Olivier (University of Arizona, Subaru Telescope, JPL)
The non-linear Curvature Wavefront Sensor (nlCWFS) is derived from the successful curvature wavefront sensing principle but uses a non-linear reconstruction algorithm to maintain sensitivity to low order modes. It can deliver diffraction-limited images in the visible. Use of the full spatial coherence of the pupil allows the nlCWFS (D/r_0)^2 gain in sensitivity, over the SHWFS, at the lowest spatial frequency. When background limited the nlCWFS sensitivity scales as D^4, a combination of D^2 gain due to the diffraction limit and D^2 gain due to the telescope's collecting power. For a 30 m telescope (TMT) with a seeing of 0.5'', the nlCWFs requires 22,500 fewer photons than the SHWFS to deliver the same wavefront measurement accuracy at the lowest spatial frequencies.
10.26698/AO4ELT5.0146- Proceeding PDF