Related papers: The VORTEX coronagraphic test bench

The Chandra X-ray observatory monitored the single cool star, AB Doradus, continuously for a period lasting 88ksec (1.98 Prot) in 2002 December with the LETG/HRC-S. The X-ray lightcurve shows significant rotational modulation. It can be…

The Programmable Liquid-crystal Active Coronagraphic Imager for the DAG telescope (PLACID) instrument is a novel high-contrast direct imaging facility that was recently installed on the new Turkish 4-m DAG telescope. In brief, PLACID…

Ablation fronts and shocks are two radiative/hydrodynamic features ubiquitous in inertial confinement fusion (ICF). A specially designed shock-tube experiment was tested on the OMEGA laser facility to observe these two features evolve at…

The coronagraph instrument on the WFIRST-AFTA mission study has two coronagraphic architectures, shaped pupil and hybrid Lyot, which may be interchanged for use in different observing scenarios. Each architecture relies on newly-developed…

The recent demonstration of electron vortex beams has opened up the new possibility of studying orbital angular momentum (OAM) in the interaction between electron beams and matter. To this aim, methods to analyze the OAM of an electron beam…

The phase-apodized-pupil Lyot coronagraph (PAPLC) is a pairing of the apodized-pupil Lyot coronagraph (APLC) and the apodizing phase plate (APP) coronagraph. We describe a numerical optimization method to obtain globally-optimal solutions…

The raw coronagraphic performance of current high-contrast imaging instruments is limited by the presence of a quasi-static speckle (QSS) background, resulting from instrumental non-common path errors (NCPEs). Rapid development of efficient…

In the context of high contrast imaging, we propose to evaluate the performance of the Apodized Pupil Lyot Coronagraph (APLC) working without Lyot Stop, namely Stop-less Lyot Coronagraph (SLLC). This coronagraph is a combination of an…

RISTRETTO is the evolution of the original idea of coupling the VLT instruments SPHERE and ESPRESSO, aiming at High Dispersion Coronagraphy. RISTRETTO is a visitor instrument that should enable the characterization of the atmospheres of…

We present a publicly available software package developed for exploring apodized pupil Lyot coronagraph (APLC) solutions for various telescope architectures. In particular, the package optimizes the apodizer component of the APLC for a…

Exoplanet imaging and spectroscopy are now routinely achieved by dedicated instruments on large ground-based observatories (e.g. Gemini/GPI, VLT/SPHERE, or Subaru/SCExAO). In addition to extreme adaptive optics (ExAO) and post-processing…

Several recent designs for planet-finding telescopes use coronagraphs operating at visible wavelengths to suppress starlight along the telescope's optical axis while transmitting any off-axis light from circumstellar material. We describe a…

The NIRC2 vortex coronagraph is an instrument on Keck II designed to directly image exoplanets and circumstellar disks at mid-infrared bands $L^\prime$ (3.4-4.1 $\mu$m) and $M_s$ (4.55-4.8 $\mu$m). We analyze imaging data and corresponding…

Cardiac disease evaluation depends on multiple diagnostic modalities: electrocardiogram (ECG) to diagnose abnormal heart rhythms, and imaging modalities such as Magnetic Resonance Imaging (MRI), Computed Tomography (CT) and echocardiography…

We study the way Lyot coronagraphs with unapodized entrance pupils respond to small, low order phase aberrations. This study is applicable to ground-based adaptive optics coronagraphs operating at 90% and higher Strehl ratios, as well as to…

Coronavirus Disease 2019 (COVID-19) has become a serious global epidemic in the past few months and caused huge loss to human society worldwide. For such a large-scale epidemic, early detection and isolation of potential virus carriers is…

The present study experimentally examines how an electron vortex beam with orbital angular momentum (OAM) undergoes diffraction through a forked grating. The nth-order diffracted electron vortex beam after passing through a forked grating…

Semantic labeling of coronary arterial segments in invasive coronary angiography (ICA) is important for automated assessment and report generation of coronary artery stenosis in the computer-aided diagnosis of coronary artery disease (CAD).…

The world's first ever ''adaptive stellar coronagraph'' facility will be the PLACID instrument, installed on Turkey's new national observatory 4-m DAG telescope. PLACID incorporates a customized spatial light modulator (SLM) acting as a…

3D printing, also called additive manufacturing, offers a new vision for optical fabrication in term of achievable optical quality and reduction of weight and cost. In this paper we describe two different ways to use this technique in the…