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Ground-based direct imaging of exoplanets at high contrast requires precise correction of atmospheric turbulence using adaptive optics (AO). The planet-to-star contrast ratio at small angular separations from the host star is often limited…

The characterization of exoplanet atmospheres using direct imaging spectroscopy requires high-contrast over a wide wavelength range. We study a recently proposed focal plane wavefront estimation algorithm that exclusively uses broadband…

Instrumentation and Methods for Astrophysics · Physics 2021-08-19 Susan F. Redmond , Laurent Pueyo , Leonid Pogorelyuk , James Noss , Scott D. Will , Iva Laginja , N. Jeremy Kasdin , Marshall D. Perrin , Remi Soummer

We propose an optomechanical design, consisting of a parity-time symmetric multilayer structure tuned at exceptional-point degeneracy (EPD), with an adjustable layer that is coupled to micromechanical springs. The deflections of this layer…

Applied Physics · Physics 2020-07-01 Rodion Kononchuk , Tsampikos Kottos

In optical imaging, light propagation is affected by the inhomogeneities of the medium. Sample-induced aberrations and multiple scattering can strongly degrade the image resolution and contrast. Based on a dynamic correction of the incident…

Context. In the context of direct imaging of exoplanets, coronagraphs are commonly proposed to reach the required very high contrast levels. However, wavefront aberrations induce speckles in their focal plane and limit their performance.…

Instrumentation and Methods for Astrophysics · Physics 2015-06-18 Johan Mazoyer , Pierre Baudoz , Raphaël Galicher , Gérard Rousset

The success of ground-based, high contrast imaging for the detection of exoplanets in part depends on the ability to differentiate between quasi-static speckles caused by aberrations not corrected by adaptive optics (AO) systems, known as…

Instrumentation and Methods for Astrophysics · Physics 2018-07-13 Alexander T. Rodack , Jared R. Males , Olivier Guyon , Benjamin A. Mazin , Michael P. Fitzgerald , Dimitri Mawet

We propose and demonstrate a system for wavefront shaping which generates optical foci through complex disordered media and achieves an enhancement factor of greater than 100,000. To exploit the 1 Megapixel capacity of a digital…

Optics · Physics 2017-04-26 HyeonSeung Yu , KyeoReh Lee , YongKeun Park

Traditional wavefront control in high-energy, high-intensity laser systems usually lacks real-time capability, failing to address dynamic aberrations. This limits experimental accuracy due to shot-to-shot fluctuations and necessitates long…

We describe and demonstrate the use of an adaptive wave front optimization scheme for enhancing the efficiency of adiabatic nanofocusing of surface plasmon polariton (SPP) waves along an ultrasharp conical gold taper. Adiabatic nanofocusing…

Servo lag errors in adaptive optics lead to inaccurate compensation of wavefront distortions. An attempt has been made to predict future wavefronts using data mining on wavefronts of the immediate past to reduce these errors. Monte Carlo…

Instrumentation and Methods for Astrophysics · Physics 2009-11-08 Akondi Vyas , M B Roopashree , B Raghavendra Prasad

We propose and demonstrate a method for the adaptive wavefront correction of dynamic multimode fiber beams for the first time. The wavefront of incident beam is reconstructed in real-time based on the complete modal information, which…

Direct imaging of extra-solar planets is now a reality, especially with the deployment and commissioning of the first generation of specialized ground-based instruments such as the Gemini Planet Imager and SPHERE. These systems will allow…

Instrumentation and Methods for Astrophysics · Physics 2016-01-20 Sandrine J. Thomas , Ruslan Belikov , Eduardo Bendek

We study a mid-order wavefront sensor (MOWFS) to address fine cophasing errors in exoplanet imaging with future large segmented aperture space telescopes. Observing Earth analogs around Sun-like stars requires contrasts down to $10^{-10}$…

Instrumentation and Methods for Astrophysics · Physics 2024-09-10 B. Buralli , M. N'Diaye , R. Pourcelot , M. Carbillet , E. H. Por , I. Laginja , L. Canas , S. Steiger , P. Petrone , M. M. Nguyen , B. Nickson , S. F. Redmond , A. Sahoo , L. Pueyo , M. D. Perrin , R. Soummer

The highest three-dimensional (3D) resolution possible in in-vivo retinal imaging is achieved by combining optical coherence tomography (OCT) and adaptive optics (AO). However, this combination brings important limitations, such as small…

Medical Physics · Physics 2020-10-21 Jules Scholler , Kassandra Groux , Kate Grieve , Claude Boccara , Pedro Mecê

Focal plane wavefront sensing is an appealing technique to cophase multiple aperture telescopes. Phase diversity, operable with any aperture configuration or source extension, generally suffers from high computing load. In this Letter, we…

Instrumentation and Methods for Astrophysics · Physics 2020-12-07 Sebastien Vievard , Aurelie Bonnefois , Frederic Cassaing , Joseph Montri , Laurent Mugnier

The use of Fourier methods in wave-front reconstruction can significantly reduce the computation time for large telescopes with a high number of degrees of freedom. However, Fourier algorithms for discrete data require a rectangular data…

Instrumentation and Methods for Astrophysics · Physics 2017-06-07 Charlotte Z. Bond , Carlos M. Correia , Jean-François Sauvage , Benoit Neichel , Thierry Fusco

We present a segment-level wavefront stability error budget for space telescopes essential for exoplanet detection. We use a detailed finite element model to relate the temperature gradient at the location of the primary mirror to wavefront…

Instrumentation and Methods for Astrophysics · Physics 2022-09-15 Ananya Sahoo , Iva Laginja , Laurent Pueyo , Remi Soummer , Laura E. Coyle , J. Scott Knight , Matthew East

Wavefront aberrations can reflect the imaging quality of high-performance optical systems better than geometric aberrations. Although laser interferometers have emerged as the main tool for measurement of transmitted wavefronts, their…

This is the second article in a series of two which report on a matrix approach for ultrasound imaging in heterogeneous media. This article describes the quantification and correction of aberration, i.e. the distortion of an image caused by…

Image and Video Processing · Electrical Eng. & Systems 2022-12-06 William Lambert , Laura A. Cobus , Justine Robin , Mathias Fink , Alexandre Aubry

The performance of an adaptive optics (AO) system on a 100m diameter ground based telescope working in the visible range of the spectrum is computed using an analytical approach. The target Strehl ratio of 60% is achieved at 0.5um with a…

Astrophysics · Physics 2009-10-31 M. Le Louarn , N. Hubin , M. Sarazin , A. Tokovinin
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