Focal-plane wavefront sensing with a photonic lantern
Extreme adaptive optics techniques are essential to reach the resolution and contrast necessary to directly image Earth-like planets around Sun-like stars using large ground-based telescopes. In particular, focal-plane wavefront sensing allows us to correct non-common path aberrations that would otherwise distort the science image while being inaccessible to the adaptive optics system. I ran experiments on the SEAL testbed at UCSC and on the Shane adaptive optics system at Lick Observatory demonstrating wavefront control using a photonic lantern. I’ve written several papers and conference proceedings on this topic:
- First laboratory demonstration of closed-loop control using a PL, SPIE 2024
- The testbed I built for photonic lantern experiments, SPIE 2025
- Experimental demonstration of the PL’s sensitivity to primary-mirror segment phasing aberrations (led by then-undergraduate Maria Cuevas), SPIE 2025
- On-sky demonstration of the PL as a wavefront sensor, ApJ 2026
- Laboratory measurements of how sensitive the PL wavefront sensor is to photon noise, SPIE 2026
- Off-axis holography characterization of a multi-PL waveguide, SPIE 2026
Control algorithms for dual-wavefront sensor single-conjugate adaptive optics
Laboratory demonstration of optimal identification and control of tip-tilt systems
I started this project in 2019, as a rising third-year undergraduate. Initially it was a pure simulation project, but I came back to it in 2021 to run laboratory tests of my simulations, as part of the UCSC Lamat REU. I published this work as an SPIE paper, and presented it at the 2022 Spirit of Lyot and SPIE conferences.
I wrote a real-time control framework for the UC Santa Cruz SEAL adaptive optics testbed, implemented a linear-quadratic-Gaussian controller with a turbulence/vibration-based physics model, and tested it in simulation and on the bench.