Experimental and on-sky demonstration of spectrally dispersed wavefront sensing using a photonic lantern

TL;DR

This paper demonstrates for the first time on-sky real-time wavefront correction using a spectrally dispersed photonic lantern sensor, advancing adaptive optics with potential for integrated spectrograph applications.

Contribution

It introduces a novel spectrally dispersed wavefront sensing method using a photonic lantern and demonstrates its effectiveness in real-time adaptive optics correction on an astronomical telescope.

Findings

Spectral dispersion improves wavefront correction fidelity.

First on-sky demonstration of spectrally dispersed photonic lantern wavefront sensing.

Potential for integrated wavefront sensing and spectroscopy in compact photonic devices.

Abstract

Adaptive optics systems are critical in any application where highly resolved imaging or beam control must be performed through a dynamic medium. Such applications include astronomy and free-space optical communications, where light propagates through the atmosphere, as well as medical microscopy and vision science, where light propagates through biological tissue. Recent works have demonstrated common-path wavefront sensors for adaptive optics using the photonic lantern, a slowly varying waveguide that can efficiently couple multi-moded light into single-mode fibers. We use the SCExAO astrophotonics platform at the 8-m Subaru Telescope to show that spectral dispersion of lantern outputs can improve correction fidelity, culminating with an on-sky demonstration of real-time wavefront control. To our best knowledge, this is the first such result for either a spectrally dispersed or a photonic lantern wavefront sensor. Combined with the benefits offered by lanterns in precision spectroscopy, our results suggest the future possibility of a unified wavefront sensing spectrograph using compact photonic devices.