Patterned liquid-crystal optics for broadband coronagraphy and wavefront sensing

TL;DR

This paper introduces advanced liquid-crystal patterned optics for broadband coronagraphy and wavefront sensing, demonstrating on-sky performance, wavelength selectivity, and new design capabilities enabled by this technology.

Contribution

It presents novel liquid-crystal designs for broadband and wavelength-specific coronagraphs and wavefront sensors, with on-sky validation and new geometric phase pattern implementations.

Findings

Successful on-sky operation of a 2-5 μm double-grating vAPP with a 360° dark hole

Development of a 1-2.5 μm grating-vAPP for SCExAO

Introduction of wavelength-selective vAPPs and advanced wavefront sensing patterns

Abstract

The direct-write technology for liquid-crystal patterns allows for manufacturing of extreme geometric phase patterned coronagraphs that are inherently broadband, e.g. the vector Apodizing Phase Plate (vAPP). We present on-sky data of a double-grating vAPP operating from 2-5 $\mu m$ with a 360-degree dark hole and a decreased leakage term of $\sim 10^{-4}$. We report a new liquid-crystal design used in a grating-vAPP for SCExAO that operates from 1-2.5$\mu m$. Furthermore, we present wavelength-selective vAPPs that work at specific wavelength ranges and transmit light unapodized at other wavelengths. Lastly, we present geometric phase patterns for advanced implementations of WFS (e.g. Zernike-type) that are enabled only by this liquid-crystal technology.