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Shack Hartmann Sensor (SHS) is inflicted with significant background noise that deteriorates the wave-front reconstruction accuracy. In this paper, a simple method to remove the back ground noise with the use of Zernike polynomials is…

Instrumentation and Methods for Astrophysics · Physics 2011-09-14 Akondi Vyas , M B Roopashree , B Raghavendra Prasad

Conventional methods of wavefront reconstruction from the raw data of the Shack-Hartmann sensor use the focal spot shifts and discard the high-frequency information about the wavefront. Phase-retrieval-based methods treat the Hartmann…

This paper studies the effects on Zernike coefficients of aperture scaling, translation and rotation, when a given aberrated wavefront is described on the Zernike polynomial basis. It proposes a new analytical method for computing the…

Instrumentation and Methods for Astrophysics · Physics 2015-06-15 Eric Tatulli

Wavefront reconstruction is a critical component in various optical systems, including adaptive optics, interferometry, and phase contrast imaging. Traditional reconstruction methods often employ either the Cartesian (pixel) basis or the…

Optics · Physics 2024-11-06 S. Howard , N. Weisse , J. Schroeder , C. Barbero , B. Alonso , I. Sola , P. Norreys , A. Döpp

We report an extensive numerical study and supporting experimental results on the spectral characterization of optical aberrations in macroscopic fluidic lenses with tunable focal distance and aperture shape. Using a Shack-Hartmann…

Optics · Physics 2023-12-19 Graciana Puentes , Fernando Minotti

Shack Hartmann wavefront sensor is a two dimensional array of lenslets which is used to detect the incoming phase distorted wavefront through local tilt measurements made by recording the spot pattern near the focal plane. Wavefront…

Instrumentation and Methods for Astrophysics · Physics 2011-08-16 Akondi Vyas , M B Roopashree , B Raghavendra Prasad

Wavefront sensing is a set of techniques providing efficient means to ascertain the shape of an optical wavefront or its deviation from an ideal reference. Due to its wide dynamical range and high optical efficiency, the Shack-Hartmann is…

Quantum Physics · Physics 2014-02-14 B. Stoklasa , L. Motka , J. Rehacek , Z. Hradil , L. L. Sanchez-Soto

The space-variant wavefront reconstruction problem inherently exists in deep tissue imaging. In this paper,we propose a framework of Shack-Hartmann wavefront space-variant sensing with extended source illumination. The space-variant…

Context. Solar Shack-Hartmann wavefront sensors measure differential wavefront tilts as the relative shift between images from different subapertures. There are several methods in use for measuring these shifts. Aims. We evaluate the…

Instrumentation and Methods for Astrophysics · Physics 2015-05-20 Mats G. Löfdahl

Shack-Hartmann wavefront sensors (SHWS) are generally used to measure the wavefront curvature of light beams. Measurement accuracy and the sensitivity of these sensors are important factors for better wavefront sensing. In this study, we…

Optics · Physics 2021-10-04 Nitin Dubey , Ravi Kumar , Joseph Rosen

The Shack-Hartmann wavefront sensor is widely used to measure aberrations induced by atmospheric turbulence in adaptive optics systems. However if there exists strong atmospheric turbulence or the brightness of guide stars is low, the…

Instrumentation and Methods for Astrophysics · Physics 2021-04-14 Peng Jia , Mingyang Ma , Dongmei Cai , Weihua Wang , Juanjuan Li , Can Li

The partial derivatives and Laplacians of the Zernike circle polynomials occur in various places in the literature on computational optics. In a number of cases, the expansion of these derivatives and Laplacians in the circle polynomials…

Mathematical Physics · Physics 2015-06-19 Augustus J. E. M Janssen

Zernike polynomials are widely used to describe the wavefront phase as they are well suited to the circular geometry of various optical apertures. Non-conventional optical systems, such as future large optical telescopes with highly…

Instrumentation and Methods for Astrophysics · Physics 2018-09-27 Pierre Janin-Potiron , Patrice Martinez , Marcel Carbillet

The term wavefront sensor refers to the entire class of devices capable of measuring the optical wavefront of the incoming beam. Although numerous solutions have been proposed so far, recent advances in structured light have opened new…

Some metrological means, such as Shack-Hartmann, deflectometry sensors or fringe projection profilometry, measure the shape of an optical surface indirectly from slope measurements. Zonal shape reconstruction, a method to reconstruct shape…

Based on image moment theory, an approach for space-variant Shack-Hartmann wavefront reconstruction is presented in this article. The relation between the moment of a pair of subimages and the local transformation coefficients is derived.…

The image degradation produced by atmospheric turbulence and optical aberrations is usually alleviated using post-facto image reconstruction techniques, even when observing with adaptive optics systems. These techniques rely on the…

Instrumentation and Methods for Astrophysics · Physics 2015-05-18 A. Asensio Ramos , A. Lopez Ariste

The classic Hartmann test consists of an array of holes to reconstruct the wavefront from the local deviation of each focal spot, and Shack-Hartmann sensor improved that with an array of microlenses. This array of microlenses imposes…

Optics · Physics 2019-12-02 Job Mendoza-Hernandez , Dorilian Lopez-Mago

The weak measurement wavefront sensor detects the phase gradient of light like the Shack-Hartmann sensor does. However, the use of one thin birefringent crystal to displace light beams results in a wavelength-dependent phase difference…

Optics · Physics 2022-05-27 Yi Zheng , Mu Yang , Zheng-Hao Liu , Jin-Shi Xu , Chuan-Feng Li , Guang-Can Guo

In typical adaptive optics applications, the atmospheric residual turbulence affects the wavefront sensor response decreasing its sensitivity. On the other hand, wavefront sensors are generally calibrated in diffraction limited condition,…

Instrumentation and Methods for Astrophysics · Physics 2023-10-10 Guido Agapito , Carmelo Arcidiacono , Simone Esposito
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