RSAA Colloquia / Seminars / Feast-of-Facts: Tuesday, 29 April 2025, 11:00-12:00; ZOOM or Duffield Lecture Theatre


Barnaby Norris

"Astrophotonics and a new era of exoplanet imaging"

Direct imaging of exoplanets and protoplanetary disks at solar-system scales promises unprecedented insights into exoplanet science, including high-resolution characterization of exoplanet surfaces, atmospheres, and biosignatures. This potential is particularly exciting in light of the upcoming generation of Extremely Large Telescopes (ELTs). However, achieving the extraordinary angular resolutions and contrasts necessary for such observations surpasses the limits of conventional technologies. Astrophotonics -- an emerging field focused on the manipulation and processing of light within integrated circuits and optical fibres -- is poised to revolutionize direct imaging of habitable-zone, Earth-like exoplanets. This technology offers precise control of light, enhanced stability, and critically, the capability to measure previously inaccessible properties of incoming starlight. For instance, on-chip nulling interferometers enable milli-arcsecond imaging scales by utilizing destructive interference to effectively suppress contaminating starlight, thus readily accessing the habitable zones around nearby stars. Additionally, photonic lanterns (a central focus of this talk) facilitate comprehensive wavefront measurement, distinguishing genuine planetary signals from atmospheric seeing and speckle noise. By simultaneously capturing amplitude, phase, spatial coherence, and spectral information, these devices integrate adaptive optics with advanced image reconstruction techniques, enabling the recovery of super-diffraction-limited images and spectra. In this presentation, I will discuss these cutting-edge astrophotonic technologies and instruments, highlight recent advancements, and explore future developments that will ultimately allow detailed imaging and high-resolution spectroscopy of habitable-zone exoplanets in reflected light.