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Experimental studies of the effect of measurement data loss on the quality of wavefront reconstruction using a Shack-Hartmann sensor in the presence of distortions from atmospheric turbulence

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JOURNAL OF OPTICAL TECHNOLOGY 2024年第8期91卷 527-532页

作者： Bolbasova, Lidia a. Lukin, Vladimir p. Soin, Egor l. Russian Acad Sci V E Zuev Inst Atmospher Opt Siberian Branch Tomsk 634055 Russia

Subject of study. The distortion of an optical laser wavefront by atmospheric turbulence is studied. Aim of study. The effect of data loss due to vignetting and central obscuration in the entrance pupil of an optical system on the Shack-Hartmann sensor reconstruction of a horizontally propagating laser wavefront distorted by atmospheric turbulence is experimentally determined. Method. Experimental studies were performed by studying the propagation of laser radiation along a horizontal atmospheric path with various vignetting and central obscuration ratios. The results were analyzed using Zernike polynomials. Main results. We describe the experimental results for the Shack-Hartmann sensor reconstruction of a horizontally propagating laser wavefront distorted by atmospheric turbulence, where the entrance pupil of the optical system was affected by vignetting and central obscuration. We show that central obscuration has no significant effect on wavefront reconstruction;however, artificially low spherical aberration values may require modification of the adaptive correction algorithm in the adaptive optics system. Coma aberration values will be artificially high in the presence of vignetting. Practical significance. Wavefront sensors are a key component in adaptive optics systems, and the measurements provided by such sensors affect the final result for correction of the optical wavefront distortions. The research results obtained herein will be important in the development of adaptive optics systems for atmospheric transmission and focusing of laser light passing through the atmosphere. (c) 2025 Optica Publishing Group

关键词： adaptive optics Laser light Modulation transfer function Optical systems Spherical aberration systems design

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Evaluating Laser Beam Parameters for Ground-to-space propagation through atmospheric Turbulence at the Geochang SLR Observatory

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CURRENT optics AND PHOTONICS 2024年第4期8卷 382-390页

作者： Pak, Ji Hyun Joo, Ji Yong Lee, Jun Ho Kim, Ji In Cho, Soo Hyung Park, Ki Soo Son, Eui Seung Kongju Natl Univ Dept Opt Engn Cheonan 31080 South Korea Kongju Natl Univ Inst Applicat & Fus Light Cheonan 31080 South Korea Hanwha Syst Seongnam 13524 South Korea Def Rapid Acquisit Technol Res Inst DRATRI Seoul 07062 South Korea

Laser propagation through atmospheric disturbances is vital for applications such as laser optical communication, satellite laser ranging (SLR), laser guide stars (LGS) for adaptive optics (AO), and laser energy transmission systems. Beam degradation, including energy loss and pointing errors caused by atmospheric turbulence, requires thorough numerical analysis. This paper investigates the impact of laser beam parameters on ground-to-space laser propagation up to an altitude of 100 km using vertical atmospheric disturbance profiles from the Geochang SLR Observatory in South Korea. The analysis is confined to 100 km since sodium LGS forms at this altitude, and beyond this point, beam propagation can be considered free space due to the absence of optical disturbances. Focusing on a 100-watt class laser, this study examines parameters such as laser wavelengths, beam size (diameter), beam jitter, and beam quality (M-2). Findings reveal that jitter, with an influence exceeding 70%, is the most critical parameter for long-exposure radius and pointing error. Conversely, M-2 , with an influence over 45%, is most significant for short-exposure radius and scintillation.

关键词： adaptive optics atmospheric disturbance Laser beam propagation Laser guide starS

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Overview of modern technologies for measuring, predicting and correcting turbulent distortions in optical waves

COMPUTER OPTICS

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COMPUTER optics 2024年第1期48卷 68-81页

作者： Lukin, V. P. Lukin, I. P. RAS VE Zuev Inst Atmospher Opt SB sq Acad Zuev 1 Tomsk 634055 Russia

This work is an analytical review of the components of modern technology for creating adaptive optics systems for correcting the distortion of optical waves propagating in a turbulent atmosphere. The work consists of the following parts: description of a technique for measuring fluctuations of optical waves in an atmospheric path, theoretical calculations of fluctuations by analytical analysis and mathematical modeling methods, technology for predicting turbulent air movement by the numerical solution of the Navier-Stokes equations and, finally, constructing adaptive optics systems that compensate for the turbulent distortions in optoelectronic image construction systems. Attention is focused on the peculiarities of fluctuations of specially created Laguerre-Gaussian and Bessel-Gaussian beams. Features of the propagation of vortex Laguerre-Gaussian and vortex Bessel-Gaussian beams for the transfer of orbital angular momentum through a turbulent medium are shown. Effects of the relative attenuation of phase and intensity fluctuations of the vortex-free Bessel-Gaussian beams in comparison with similar characteristics of the Gaussian beams are found. The integral scale of the coherence degree of the vortex Bessel-Gaussian beams and vortex conic waves is revealed to be highly sensitive to the influence of atmospheric turbulence, in contrast to the coherence radius of these beams and waves. Arguments are given in favor of the feasibility of constructing adaptive optical systems for a wide-aperture solar telescope operating under a strong atmospheric turbulence.

关键词： optical waves atmospheric turbulence measurements fluctuations Laguerre-Gaussian beams Bessel-Gaussian beams adaptive correction

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Analysis of the impact of turbulence strength fluctuations on the performance of atmospheric electro-optics systems 13

Analysis of the impact of turbulence strength fluctuations o...

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Laser Communication and propagation through the Atmosphere and Oceans XIII 2024

作者： Hammel, Stephen Weyrauch, Thomas Filimonov, Grigorii Vorontsov, Mikhail Naval Information Warfare Center Pacific San DiegoCA United States Intelligent Optics Laboratory Department of Electro-Optics & Photonics School of Engineering University of Dayton DaytonOH45469 United States

ISBN: (纸本)9781510679542

We emphasize the requirement for a validated simulation environment to assess the impact of changes in atmospheric turbulence strength throughout the day and year on the performance of atmospheric electro-optics (EO) systems such as directed energy, power beaming, and laser communications. In the proposed approach, site-specific data from persistent measurements of atmospheric parameters, for instance, turbulence strength, represent the variability of atmospheric propagation conditions. Together with atmospheric models and numerical weather predictions, the measured data are utilized to build atmospheric propagation models for wave-optics simulations of atmospheric EO systems. We demonstrate this approach with a database of continuous (24/7) Cn2 and meteorological measurements on a 7 km atmospheric propagation path at the University of Dayton test range for predictive modeling of laser beam propagation parameters and their fluctuations during diurnal and monthly cycles. We analyze a specific laser beam director system configuration, both with and without the implementation of adaptive optics beam control. The proposed technique provides a pathway to a comprehensive predictive performance evaluation of diverse atmospheric EO systems, allowing for statistical and interactive parametric analysis. © 2024 SPIE.

关键词： adaptive optics

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Simulation of wave propagation through turbulent media utilizing the split-step beam propagation method incorporating light attenuation due to aerosol scatter

Simulation of wave propagation through turbulent media utili...

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conference on Unconventional Imaging, Sensing, and adaptive optics

作者： Pawlowski, Barry Wells, Jonathan D. Pinzhoffer, Kevin Naval Informat Warfare Ctr Atlantic One Innovat Dr Hanahan SC 29410 USA

ISBN: (纸本)9781510679597;9781510679580

Wave optics simulations study the effect of beam propagation through the atmosphere;one notable method is the split-step beam propagation method. Current atmospheric propagation software utilizes an alternating series of Fresnel propagation and phase accumulation methods through screens which are statistically representative of the atmospheric turbulence along a line-of-sight path. From this assumption the scintillation parameter along the laser path relies on an atmospheric structure parameter, C-n(2), and is typically measured using a path averaged scintillometer. While this works well for links established in static atmospheric conditions in harsher environments such as high precipitation rates, heavy fog, or clouds demand a more rigorous approach. Thus, current software typically over-predicts beam performance of links in harsh conditions. This work proposes a model in which scattering is computed from a "first principles" approach, i.e. the full Mie series is calculated at several locations along the simulated beam path. The scattering results are then combined with the traditional split-step beam propagation method through a correction factor to provide a model of attenuation on beam performance. Results show that the addition of the extinction efficiency factor reduced the overall intensity on target by a significant margin as compared to the traditional split-step beam propagation method. More work is needed to verify the utilization of the Mie scattering extinction along with the log-amplitude variance typically utilized to model the turbulence phase.

关键词： optics simulation atmospheric turbulence attenuation split-step beam propagation

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Profiling RATS generated turbulence with SMASH

Profiling RATS generated turbulence with SMASH

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conference on Unconventional Imaging, Sensing, and adaptive optics

作者： Oescha, Denis W. Sexauer, Michael S. Horst, Samuel B. Afanador, Shyheim N. Beason, Melissa K. Leidos Albuquerque NM 87106 USA US Air Force Res Lab Directed Energy Directorate Kirtland AFB NM USA BlueHalo Albuquerque NM USA US Air Force Inst Technol ENP Wright Patterson AFB OH 45433 USA

ISBN: (纸本)9781510679597;9781510679580

The Reflective atmospheric Turbulence Simulator (RATS) in the Air Force Research Laboratory's Beam Control Laboratory is used to impart realistic distortions to a propagating wavefront for testing in the advancement of adaptive optical technologies. Here RATS is being used to simulate turbulence conditions over which the Small Mobile atmospheric Sensing Hartmann (SMASH) system has typically operated. An optical clone of the SMASH system installed on the optical bench behind RATS measures the imparted optical disturbance and makes an estimate of the turbulence profile. The results are compared with the profile calculated based on the configuration of the RATS system.

关键词： Turbulence Scintillation Wavefront sensors Profiling Air force Geometrical optics atmospheric propagation atmospheric optics atmospheric sensing Optical testing

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On Feed-Forward Neural-Network-Based atmospheric Tomography 39

On Feed-Forward Neural-Network-Based Atmospheric Tomography

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39th International conference on Image and Vision Computing New Zealand

作者： Hopkins, Daniel Yang, Le Clare, Richard Univ Canterbury Elect & Comp Engn Christchurch New Zealand

ISBN: (纸本)9798331518783;9798331518776

Imaging an astronomical object from a ground location suffers from atmospheric turbulence degrading the quality of the image. adaptive optics systems use bright guide-stars to estimate the aberration and correct for it, improving the imaging quality. For objects with an angular distance outside the isoplanatic patch of a bright guide-star, atmospheric tomography can be employed as an extension to adaptive optics, estimating the aberration for those targets. This paper explores the efficacy of a feed-forward neural-network-based model for reconstruction of the target phase aberration, showing that it performs better than a least-squares atmospheric tomography method.

关键词： adaptive optics atmospheric tomography machine learning telescope wavefront Zernike polynomials

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Shack-Hartmann Characterization of atmospheric Turbulence Simulated with the Reflective atmospheric Turbulence Simulator

Shack-Hartmann Characterization of Atmospheric Turbulence Si...

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conference on Unconventional Imaging, Sensing, and adaptive optics

作者： Horse, Samuel B. Oesch, Denis W. Afanador, Shyheim N. Sexauer, Michael S. BlueHalo Albuquerque NM 87123 USA Leidos Albuquerque NM USA US Air Force Res Lab Directed Energy Directorate Kirtland AFB NM USA

ISBN: (纸本)9781510679597;9781510679580

The Reflective atmospheric Turbulence Simulator (RATS) is an instrument used to simulate the propagation of light through atmospheric turbulence. RATS can simulate up to six layers of atmospheric turbulence using reflective phase wheels with many configurations that can simulate a broad range of atmospheric turbulence conditions. Two Shack-Hartmann wavefront sensors are integrated with RATS. One of these Shack-Hartmann wavefront sensors has an effective aperture size of 40cm, and the other has an effective aperture size of 6.75cm. We simulated propagation through atmospheric turbulence using RATS and made measurements of turbulence parameters using the two Shack-Hartmann wavefront sensors. In this paper, we compare the measurements of turbulence parameters from both Shack-Hartmann wavefront sensors to each other as well as to the theoretical values for atmosphere turbulence simulated by RATS.

关键词： atmospheric turbulence atmospheric characterization Shack-Hartmann

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Laser propagation influence research considering the atmospheric characteristics of South Korea 7

Laser propagation influence research considering the atmosph...

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Environmental Effects on Light propagation and adaptive systems VII 2024

作者： Joo, J.Y. Park, J.H. Han, S.G. Lee, J.H. Department of Optical Engineering Kongju National University Cheonan31080 Korea Republic of

ISBN: (纸本)9781510680968

This paper aims to analyze the characteristics of laser beam propagation from ground to space through atmospheric turbulence at the Gochang SLR Observatory in South Korea. To address issues such as energy loss and pointing errors caused by atmospheric turbulence in various applications like laser optical communication, satellite laser ranging (SLR), adaptive optics systems, and laser energy transmission, we systematically analyzed how laser beam parameters are affected by atmospheric conditions. The study utilizes a 100-watt-class laser to simulate beam propagation up to 100 km altitude, focusing on parameters such as laser wavelength, beam size (diameter), beam jitter, and beam quality (M2) and their impact on long-exposure and short-exposure beam radius. Key findings reveal that beam jitter is the most influential parameter for the long-exposure radius, while beam quality (M2) significantly affects the short-exposure radius. These findings provide critical guidance for optimizing laser system performance under varying atmospheric conditions, potentially contributing to advancements in laser communication and weapon systems. © 2024 SPIE.

关键词： adaptive optics

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Tracking limitations imposed by atmospheric turbulence without adaptive-optics compensation

Tracking limitations imposed by atmospheric turbulence witho...

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propagation Through and Characterization of atmospheric and Oceanic Phenomena, pcAOP 2024 - Part of Optica Imaging Congress

作者： Kalensky, Matthew Getts, Darren Spencer, Mark F. Integrated Engagement Systems Department Naval Surface Warfare Center Dahlgren Division DahlgrenVA United States Joint Directed Energy Transition Office WashingtonDC United States

We derive a modified fundamental tracking frequency, which is applicable for beam-control systems that do not employ adaptive-optics compensation. We show that if higher-order aberrations are not compensated, there ar... 详细信息

关键词： adaptive optics

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