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We report the experimental results of a serially conjoined nuller system, which combines a type of Lyot coronagraph with a fiber nuller. The utilized one-dimensional diffraction-limited coronagraph (1DDLC) has promising features (binary…

Instrumentation and Methods for Astrophysics · Physics 2025-07-28 Satoshi Itoh , Taro Matsuo , Reiki Kojima , Takahiro Sumi , Motohide Tamura

Decentralized optimization for non-convex problems are now demanding by many emerging applications (e.g., smart grids, smart building, etc.). Though dramatic progress has been achieved in convex problems, the results for non-convex cases,…

Optimization and Control · Mathematics 2022-08-30 Yu Yang , Guoqiang Hu , Costas J. Spanos

The segmented coronagraph design and analysis (SCDA) study is a coordinated effort, led by Stuart Shaklan (JPL) and supported by NASA's Exoplanet Exploration Program (ExEP), to provide efficient coronagraph design concepts for exoplanet…

Instrumentation and Methods for Astrophysics · Physics 2017-12-07 Garreth Ruane , Jeffrey Jewell , Dimitri Mawet , Stuart Shaklan , Christopher C. Stark

We introduce ergonomic-centric holography, an algorithmic framework that simultaneously optimizes for realistic incoherent defocus, unrestricted pupil movements in the eye box, and high-order diffractions for filtering-free holography. The…

Graphics · Computer Science 2023-06-21 Liang Shi , DongHun Ryu , Wojciech Matusik

Gaussian aperture pupil masks (GAPMs) can in theory achieve the contrast requisite for directly imaging an extrasolar planet. We outline the process of fabricating and testing a GAPM for use on the Penn State near-IR Imager and Spectrograph…

Astrophysics · Physics 2007-05-23 J. H. Debes , J. Ge , C. Mendelowitz , A. Watson

This paper introduces an analytical method to calculate segment-level wavefront error tolerances in order to enable the detection of faint extra-solar planets using segmented telescopes in space. This study provides a full treatment of…

Instrumentation and Methods for Astrophysics · Physics 2021-03-31 Iva Laginja , Remi Soummer , Laurent M. Mugnier , Laurent Pueyo , Jean-Francois Sauvage , Lucie Leboulleux , Laura Coyle , J. Scott Knight

Here we assess the spectral and imaging properties of Fabry P\'erot etalons when located in solar magnetographs. We discuss the chosen configuration (collimated or telecentric) for both ideal and real cases. For the real cases, we focus on…

Instrumentation and Methods for Astrophysics · Physics 2019-03-18 F. J. Bailén , D. Orozco Suárez , J. C. del Toro Iniesta

Stellar coronagraph performance is highly sensitive to optical aberrations. In order to effectively suppress starlight for exoplanet imaging applications, low-order wavefront aberrations entering a coronagraph such as tip-tilt, defocus and…

Instrumentation and Methods for Astrophysics · Physics 2015-06-17 Hari Subedi , Neil T. Zimmerman , N. Jeremy Kasdin , Kathleen Cavanagh , A J Eldorado Riggs

We present a new method for numerical propagation through Lyot-style coronagraphs using finite occulting masks. Standard methods for coronagraphic simulations involve Fast Fourier Transforms (FFT) of very large arrays, and computing power…

Astrophysics · Physics 2009-11-13 Remi Soummer , Laurent Pueyo , Anand Sivaramakrishnan , Robert J. Vanderbei

We describe a coronagraphic optic for use with CONICA at the VLT that provides suppression of diffraction from 1.8 to 7 lambda/D at 4.05 microns, an optimal wavelength for direct imaging of cool extrasolar planets. The optic is designed to…

Instrumentation and Methods for Astrophysics · Physics 2015-05-19 Matthew A. Kenworthy , Sascha P. Quanz , Michael R. Meyer , Markus E. Kasper , Rainer Lenzen , Johanan L. Codona , Julien H. V. Girard , Philip M. Hinz

ADITYA-L1 is India's first space mission to study the Sun from Lagrangian 1 position. { \textit{Visible Emission Line Coronagraph}} (VELC) is one of the seven payloads in ADITYA-L1 mission scheduled to be launched around 2020. One of the…

Solar and Stellar Astrophysics · Physics 2018-08-01 Ritesh Patel , K Amareswari , Vaibhav Pant , Dipankar Banerjee , Sankarasubramanian K , Amit Kumar

The Galactic centre and its surrounding space are important in studying galaxy-scale evolution, and stellar populations therein are expected to have imprints of the long-term evolution. Interstellar extinction, however, severely limits…

Astrophysics of Galaxies · Physics 2018-10-03 Noriyuki Matsunaga

We have reported previously on a new method we are developing for using image-based information to improve global coronal magnetic field models. In that work we presented early tests of the method which proved its capability to improve…

Solar and Stellar Astrophysics · Physics 2017-08-02 Shaela I. Jones , Joseph M. Davila , Vadim M. Uritsky

Hyperspherical Prototypical Learning (HPL) is a supervised approach to representation learning that designs class prototypes on the unit hypersphere. The prototypes bias the representations to class separation in a scale invariant and known…

Machine Learning · Computer Science 2025-04-18 Martin Lindström , Borja Rodríguez-Gálvez , Ragnar Thobaben , Mikael Skoglund

The Mid-infrared ELT Imager and Spectrograph (METIS) is a first-generation instrument for the Extremely Large Telescope (ELT), Europe's next-generation 39 m ground-based telescope for optical and infrared wavelengths. METIS will offer…

Despite its success in self-supervised learning, contrastive learning is less studied in the supervised setting. In this work, we first use a set of pilot experiments to show that in the supervised setting, the cross-entropy loss objective…

Computation and Language · Computer Science 2026-02-13 Liz Li , Wei Zhu

In this paper, we presented an efficient algorithm to implement the regularization reconstruction of SPECT. Image reconstruction with priori assumptions is usually modeled as a constrained optimization problem. However, there is no…

Optimization and Control · Mathematics 2013-06-07 Shousheng Luo , Tie Zhou

Existing Electric Field Conjugation (EFC) methods are not suited for treating small polarization effects, referred to here as cross polarization. EFC utilizes a deformable mirror (DM) to nullify the electric fields from the host star within…

Instrumentation and Methods for Astrophysics · Physics 2024-10-11 Richard A. Frazin

Adaptive optic (AO) systems delivering high levels of wavefront correction are now common at observatories. One of the main limitations to image quality after wavefront correction comes from atmospheric refraction. An Atmospheric dispersion…

Instrumentation and Methods for Astrophysics · Physics 2018-01-31 Prashant Pathak , Olivier Guyon , Nemanja Jovanovic , Julien Lozi , Frantz Martinache , Yosuke Minowa , Tomoyuki Kudo , Takayuki Kotani , Hideki Takami

We describe and summarize the optical challenges for future instrumentation for Extremely Large Telescopes (ELTs). Knowing the complex instrumental requirements is crucial for the successful design of 30-60m aperture telescopes. After all,…

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