Photonic Technologies for a Pupil Remapping Interferometer

TL;DR

This paper explores the development of integrated photonic technologies for pupil remapping interferometry, aiming to enhance stability, miniaturization, and functionality of interferometric instruments for astronomical observations.

Contribution

It introduces new photonic waveguide structures that enable compact, stable, and versatile interferometric devices suitable for observatory and spacecraft applications.

Findings

Photonic waveguide structures can be fabricated into a single substrate.

These structures improve stability and robustness of interferometric devices.

Potential for integrating multiple optical functions on a chip.

Abstract

Interest in pupil-remapping interferometry, in which a single telescope pupil is fragmented and recombined using fiber optic technologies, has been growing among a number of groups. As a logical extrapolation from several highly successful aperture masking programs underway worldwide, pupil remapping offers the advantage of spatial filtering (with single-mode fibers) and in principle can avoid the penalty of low throughput inherent to an aperture mask. However in practice, pupil remapping presents a number of difficult technological challenges including injection into the fibers, pathlength matching of the device, and stability and reproducibility of the results. Here we present new approaches based on recently-available photonic technologies in which coherent three-dimensional waveguide structures can be sculpted into bulk substrate. These advances allow us to miniaturize the photonic processing into a single, robust, thermally stable element; ideal for demanding observatory or spacecraft environments. Ultimately, a wide range of optical functionality could be routinely fabricated into such structures, including beam combiners and dispersive or wavelength selective elements, bringing us closer to the vision of an interferometer on a chip.