title: High-performance 3D waveguide architecture for astronomical pupil-remapping interferometry.
abstract: The detection and characterization of extra-solar planets is a major theme driving modern astronomy. Direct imaging of exoplanets allows access to a parameter space complementary to other detection methods, and potentially the characterization of exoplanetary atmospheres and surfaces. However achieving the required levels of performance with direct imaging from ground-based telescopes (subject to Earth's turbulent atmosphere) has been extremely challenging. Here we demonstrate a new generation of photonic pupil-remapping devices which build upon the Dragonfly instrument, a high contrast waveguide-based interferometer. This new generation overcomes problems caused by interference from unguided light and low throughput. Closure phase measurement scatter of only ∼ 0.2° has been achieved, with waveguide throughputs of > 70%. This translates to a maximum contrast-ratio sensitivity between star and planet at 1λ/D (1σ detection) of 5.3 × 10(-4) (with a conventional adaptive-optics system) or 1.8 × 10(-4) (with 'extreme-AO'), improving even further when random error is minimized by averaging over multiple exposures. This is an order of magnitude beyond conventional pupil-segmenting interferometry techniques (such as aperture masking), allowing a previously inaccessible part of the star to planet contrast-separation parameter space to be explored.
authors.forename: Barnaby
authors.initials: B
authors.lastname: Norris
authors.forename: Nick
authors.initials: N
authors.lastname: Cvetojevic
authors.forename: Simon
authors.initials: S
authors.lastname: Gross
authors.forename: Nemanja
authors.initials: N
authors.lastname: Jovanovic
authors.forename: Paul N
authors.initials: PN
authors.lastname: Stewart
authors.forename: Ned
authors.initials: N
authors.lastname: Charles
authors.forename: Jon S
authors.initials: JS
authors.lastname: Lawrence
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Withford
authors.forename: Peter
authors.initials: P
authors.lastname: Tuthill