Astronomical demonstration of an optical vortex coronagraph

Swartzlander, Grover A.; Ford, Erin L.; Abdul-Malik, Rukiah S.; Close, Laird M.; Peters, Mary Anne; Palacios, David; Wilson, Daniel W.

doi:10.1364/oe.16.010200

Cited by 179 publications

(82 citation statements)

References 21 publications

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“…A first investigation in this field has been done by Jenkins (2008) in a paper concerning the coronagraphy, in which it was analytically demonstrated that an OV coronagraph can give good performances also in ground-based telescopes operating with a partial correction of the atmospheric turbulence. The feasibility of ground-based = 2 OV coronagraphy has been demonstrated very recently by Swartzlander et al (2008). In this Paper we present the results of the direct observation of OVs generated with starlight beams at the Asiago 122 cm telescope.…”

Section: Introductionmentioning

confidence: 94%

Optical vortices with starlight

Anzolin

Tamburini²,

Bianchini³

et al. 2008

A&A

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Aims. In this paper we present our first observations at the Asiago 122 cm telescope of = 1 optical vortices generated with starlight beams. Methods. We used a fork-hologram blazed at the first diffraction order as a phase modifying device. The multiple system Rasalgethi (α Herculis) in white light and the single star Arcturus (α Bootis) through a 300 Å bandpass were observed using a fast CCD camera. In the first case we could adopt the Lucky Imaging approach to partially correct for seeing effects. Results. For both stars, the optical vortices could be clearly detected above the smearing caused by the mediocre seeing conditions. The profiles of the optical vortices produced by the beams of the two main components of the α Her system are consistent with numerically simulated on-axis and off-axis optical vortices. The optical vortices produced by α Boo can also be reproduced by numerical simulations. Our experiments confirm that the ratio between the intensity peaks of an optical vortex can be extremely sensitive to off-axis displacements of the beam. Conclusions. Our results give insights for future astronomical applications of optical vortices both for space telescopes and groundbased telescopes with good seeing conditions and adaptive optics devices. The properties of optical vortices can be used to perform high precision astrometry and tip/tilt correction of the isoplanatic field. We are now designing a = 2 optical vortex coronagraph around a continuous spiral phase plate. We also point out that optical vortices could find extremely interesting applications also in the infrared and radio wavelengths.

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Section: Introductionmentioning

confidence: 94%

Optical vortices with starlight

Anzolin

Tamburini²,

Bianchini³

et al. 2008

A&A

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“…The VC suppresses the light from a star, allowing direct detection of dim companions, exoplanets, and circumstellar disks. Imaging objects with a VC, which are otherwise buried in the noise associated with the bright host star, has been demonstrated in laboratory (e.g., Mawet et al 2009;Delacroix et al 2013) and on-sky observations (e.g., Swartzlander et al 2008;Mawet et al 2010;Serabyn et al 2010;Absil et al 2013;Defrère et al 2014).…”

Section: Introductionmentioning

confidence: 99%

Lyot-plane phase masks for improved high-contrast imaging with a vortex coronagraph

Ruane

Huby

Absil

et al. 2015

A&A

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Context. The vortex coronagraph is an optical instrument that precisely removes on-axis starlight allowing for high contrast imaging at small angular separation from the star, a crucial capability for direct detection and characterization of exoplanets and circumstellar disks. Telescopes with aperture obstructions, such as secondary mirrors and spider support structures, require advanced coronagraph designs to provide adequate starlight suppression. Aims. We introduce a phase-only Lyot-plane optic to the vortex coronagraph, which offers improved contrast performance on telescopes with complicated apertures. Potential solutions for the European Extremely Large Telescope (E-ELT) are described. Methods. Adding a Lyot-plane phase mask relocates residual starlight away from a region of the image plane, thereby reducing stellar noise and improving sensitivity to off-axis companions. The phase mask is calculated using an iterative phase retrieval algorithm. Results. Numerically, we achieve a contrast on the order of 10 −6 for a companion with angular displacement as small as 4λ/D with an E-ELT type aperture. Even in the presence of aberrations, improved performance is expected compared to either a conventional vortex coronagraph or an optimized pupil plane phase element alone.

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“…-Singular optics is the study of light waves with a phase singularity [1]. For two decades, since the experimental discovery of optical vortices [2], study of singular properties in the scalar theory of light has led to fascinating applications in various areas of physics [3][4][5][6][7][8]. Much more recently, the concepts and experimental setups from singular optics found their way to electron microscopes [9][10][11].…”

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confidence: 99%

Spin effects in electron vortex states

Boxem¹,

Verbeeck²,

Partoens³

2013

EPL

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-The recent experimental realization of electron vortex beams opens up a wide research domain previously unexplored. The present paper explores the relativistic properties of these electron vortex beams, and quantifies deviations from scalar wave theory. It is common in electron optics to use the Schrödinger equation neglecting spin. The present paper investigates the role of spin and the total angular momentum Jz and how it pertains to the vortex states.As an application, we also investigate if it is possible to use holographic reconstruction to create novel total angular momentum eigenstates in a Transmission Electron Microscope. It is demonstrated that relativistic spin coupling effects disappear in the paraxial limit, and spin effects in holographically created electron vortex beams can only be exploited by using specialized magnetic apertures.

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Astronomical demonstration of an optical vortex coronagraph

Cited by 179 publications

References 21 publications

Optical vortices with starlight

Optical vortices with starlight

Lyot-plane phase masks for improved high-contrast imaging with a vortex coronagraph

Spin effects in electron vortex states

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