Into nonlinearity and beyond for Zernike-like wavefront sensors
arXiv:2401.08090 · doi:10.1051/0004-6361/202346939
Abstract
Context: Telescopes like the Extremely Large Telescope (ELT) and the Giant Magellan Telescope (GMT) will be used together with extreme adaptive optics (AO) instruments to directly image Earth-like planets. The AO systems will need to perform at the fundamental limit in order to image Earth twins. A crucial component is the wavefront sensor. Interferometric wavefront sensors, such as the Zernike wavefront sensor (ZWFS), have been shown to perform close to the fundamental sensitivity limit. However, sensitivity comes at the cost of linearity; the ZWFS has strong nonlinear behavior. Aims: The aim of this work is to increase the dynamic range of Zernike-like wavefront sensors by using nonlinear reconstruction algorithms combined with phase sorting interferometry (PSI) and multi-wavelength measurements. Methods: The response of the ZWFS is explored analytically and numerically. Results: The proposed iterative (non)linear reconstructors reach the machine precision for small aberrations (<0.25 rad rms). Coupling the nonlinear reconstruction algorithm with PSI increases the dynamic range of the ZWFS by a factor of three to about 0.75 rad rms. Adding multiple wavebands doubles the dynamic range again, to 1.4 radians rms. Conclusion: The ZWFS is one of the most sensitive wavefront sensors, but has a limited dynamic range. The ZWFS will be an ideal second-stage wavefront sensor if it is combined with the proposed nonlinear reconstruction algorithm.
arXiv commentAccepted by A&A
References in corpus (12)
- A Giant Planet Candidate near a Young Brown Dwarf
- Limits of Adaptive Optics for high contrast imaging
- Fast computation of Lyot-style coronagraph propagation
- Calibration of quasi-static aberrations in exoplanet direct-imaging instruments with a Zernike phase-mask sensor
- Calibration of quasi-static aberrations in exoplanet direct-imaging instruments with a Zernike phase-mask sensor. II. Concept validation with ZELDA on VLT/SPHERE
- Calibration of quasi-static aberrations in exoplanet direct-imaging instruments with a Zernike phase-mask sensor. III. On-sky validation in VLT/SPHERE
- Simultaneous phase and amplitude aberration sensing with a liquid-crystal vector-Zernike phase mask
- Variation on a Zernike wavefront sensor theme: optimal use of photons
- On-sky verification of Fast and Furious focal-plane wavefront sensing: Moving forward toward controlling the island effect at Subaru/SCExAO
- Visible and Near Infrared Laboratory Demonstration of a Simplified Pyramid Wavefront Sensor
- Laboratory verification of 'Fast & Furious' phase diversity: Towards controlling the low wind effect in the SPHERE instrument
- The Bi-O-edge wavefront sensor: How Foucault-knife-edge variants can boost eXtreme Adaptive Optics