High Performance Lyot and Piaa Coronagraphy for Arbitrarily Shaped Telescope Apertures

Abstract

Two high performance coronagraphic approaches compatible with segmented and obstructed telescope pupils are described. Both concepts use entrance pupil amplitude apodization and a combined phase and amplitude focal plane mask to achieve full coronagraphic extinction of an on-axis point source. While the first concept, named Apodized Pupil Complex Mask Lyot Coronagraph (APCMLC), relies on a transmission mask to perform the pupil apodization, the second concept, named Phase-Induced Amplitude Apodization complex mask coronagraph (PIAACMC), uses beam remapping for lossless apodization. Both concepts theoretically offer complete coronagraphic extinction (infinite contrast) of a point source in monochromatic light, with high throughput and sub-λ/D inner working angle, regardless of aperture shape. The PIAACMC offers nearly 100% throughput and approaches the fundamental coronagraph performance limit imposed by first principles. The steps toward designing the coronagraphs for arbitrary apertures are described for monochromatic light. Designs for the APCMLC and the higher performance PIAACMC are shown for several monolith and segmented apertures, such as the apertures of the Subaru Telescope, Giant Magellan Telescope (GMT), Thirty Meter Telescope (TMT), the European Extremely Large Telescope (E-ELT) and the Large Binocular Telescope (LBT). Performance in broadband light is also quantified, suggesting that the monochromatic designs are suitable for use in up to 20% wide spectral bands for ground-based telescopes.

Active Correction of Aperture Discontinuities-Optimized Stroke Minimization. II. Optimization for Future Missions

“…First, we need to understand precisely how the optimum in Fresnel number is impacted by parameters such as size of the DH, number of actuators, type of aperture, and spectral bandwidth. Second, we need to prove that this technique can be used with fixed mirror apodizing techniques (PIAA, PAVC, Guyon et al 2014;Fogarty et al 2017b) (Shaklan & Green 2006;Give'On et al 2006;Pueyo & Kasdin 2007). However, they were usually used to determine surface quality limits of the optics and/or applied to DM optical design in the proposed Michelson interferometer configuration.…”

Polynomial Apodizers for Centrally Obscured Vortex Coronagraphs

“…For each shaped-mirror PAVC, except for the charge 4 PAVC with secondary mirror radius R S /R P = 0.1, the mirror shapes we calculate severely distort the off-axis point spread function (PSF) and result in a narrow range of angular separations from the onaxis star where even a modest encircled energy throughput can be obtained. Therefore, we propose using inverse mirrors placed after the Lyot stop in Stage C in Figure 7, similar to the inverse optics proposed for PIAA mirrors (Guyon et al 2005(Guyon et al , 2014. Our estimate of the encircled energy throughput after the off-axis PSF is restored by inverse optics is shown by the green curve for each coronagraph design in Figure 11.…”

“…Recently, protoplanetary discs and massive, young exoplanets have been directly imaged using coronagraphs to suppress starlight to the level where these orbiting bodies can be observed (Marois et al 2008;Kalas et al 2008;Lagrange et al 2009;Marois et al 2010;Andrews et al 2011;Carson et al 2013;Kuzuhara et al 2013;Rameau et al 2013;Oppenheimer et al 2013;Mancini et al 2015;Macintosh et al 2015;Wagner et al 2015;Pueyo et al 2015). However, observing fainter objects, such as Earth-like exoplanets, with future observatories poses a challenge for coronagraph designs, which will need to be adapted to the obstructed pupil geometries of telescopes with on-axis secondary mirrors and segmented primary mirrors (Pueyo & Norman 2013;Soummer et al 2011;Guyon et al 2014).…”

“…Fixed mirror apodization has also been combined with some of the complex coronagraph designs described above, such as the PIAA complex mask coronagraph (PIAACMC), which combines PIAA with a complex focal plane mask (Guyon et al 2014). These recent instrument designs depart considerably from the coronagraph proposed in Lyot (1939), and represent substantial progress towards achieving terrestrial exoplanet direct imaging capability.…”

Performance characterization of a phase-induced amplitude apodization complex focal plane mask

“…Many coronagraph designs have been developed, and in this paper we focus on a particularly high performance design: the Phase-Induced Amplitude Apodization Complex Mask Coronagraph (PIAACMC) [1,2]. A schematic of the PIAACMC design is shown in Fig.…”