Adaptive optics

About: Adaptive optics is a research topic. Over the lifetime, 13352 publications have been published within this topic receiving 173364 citations. The topic is also known as: AO & Adaptive optics.

Imaging Through Turbulence

Abstract: Introduction Overview of the Problem Area Historical Overview of Imaging Through Turbulence Overview of the Book Background: Fourier and Statistical Optics Fourier Optics Statistical Optics Turbulence Effects on Imaging Systems Index of Refraction Fluctuations in the Atmosphere Statistics of Index of Refraction Fluctuations Wave Propagation through Random Media First-Order Turbulence Effects on Incoherent Imaging Modal Expansions of Phase Perturbation Phase Screen Generation Speckle Imaging Techniques Introduction Overview of Speckle Imaging Speckle Interferometry Fourier Phase Estimation Techniques Image Reconstruction for Speckle Imaging Conclusion Adaptive Optical Imaging Systems Introduction Factors that Degrade AOI Systems Performance Adaptive Optical System Components and Models AOI System Performance Modeling Summary Hybrid Imaging Techniques Introduction Deconvolution from Wavefront Sensing Methods Involving Adaptive Optics Conclusion Index

Adaptive Optics in Astronomy

Abstract: Optical observations by ground‐based astronomers have long been limited by the distorting effects of the Earth's atmosphere. Primary mirrors have been polished to exquisite accuracy for telescopes with apertures as large as 10 meters, but at optical wavelengths these can deliver an angular resolution typically no better than that of a 25‐cm telescope, as atmospheric turbulence deforms the image on a millisecond time scale. One (highly expensive) approach to overcome this problem has been to loft instruments such as the Hubble Space Telescope above the atmosphere. Another approach, pursued by instrument builders in the astronomy community and their counterparts in the military, has been to design electro‐optical systems that measure and undo the effects of clear‐air turbulence in real time. (See figure 1.) A number of such adaptive optic devices have already been built and operated on large ground‐based telescopes, delivering near‐diffraction‐limited performance at infrared and visible wavelengths. With th...

Phase Retrieval And Diversity In Adaptive Optics

Abstract: Wavefront sensing by phase retrieval implies extraction of the Fourier transform of a complex signal based on observation of the modulus of the signal Only the image intensity from a system's focal plane array is required to estimate the phase aberrations These estimates are used to derive control signals to align (or to maintain alignment of) the optical system The concept can be used in both a predetection and postdetection mode In the former, the control system labors to keep the optics in a diffraction-limited mode all the time In the latter, the control system induces a phase or wavelength diversity that allows successive images to be restored to nearly diffraction-limited quality by postprocessing of the image This second mode is particularly interesting because it will reduce the design effort for both the optical system and the control system How the phase or wavelength diversity is achieved is not clear at this time If the method has utility, it provides an interesting challenge to designers of optical devices In this paper we describe the mathematics of the technique and show some computer simulations which involve both point sources and extended objects

Pupil plane wavefront sensing with an oscillating prism

Abstract: A compact pupil plane wavefront sensor is described, which is able to image on a single detector four images of the pupil, containing information on the gradient of the incoming wavefront. The wavefront sensor consists of a lens relay and an oscillating pyramidal-shaped prism. The gain of the device is driven by the amplitude of the oscillations, while the sampling is determined by the focal length of the lens relay. This wavefront sensor can be conveniently used for astronomical adaptive optics purposes because of its flexibility to match the brightness of the reference source used (varying the sampling) and the seeing conditions (varying the gain).