Principles of Adaptive Optics describes the foundations, principles, and applications of adaptive optics (AO) and its enabling technologies. This leading textbook addresses the fundamentals of AO at the core of astronomy, high-energy lasers, biomedical imaging, and optical communications.
Key Features:
- Numerous examples to explain and support the underlying principles
- Hundreds of new references to support the topics that are addressed
- End-of-chapter questions and exercises
- A complete system design example threaded through each chapter as new material is introduced
Chapter 1 History and Background
1.1 Introduction
1.2 History
1.3 Physical Optics
1.3.1 Propagation with aberrations
1.3.2 Imaging with aberrations
1.3.3 Representing the wavefront
1.3.3.1 Power series representation
1.3.3.2 Zernike series
1.3.3.3 Zernike annular polynomials
1.3.3.4 Lowest aberration modes
1.3.4 Interference
1.4 Radiometry
1.4.1 Solid Angle
1.4.2 Radiative Transfer
1.5 Terms in Adaptive Optics
Spot Size
Beam Divergence
Beam Quality
Jitter
Power-in-the-Bucket
Brightness
Astronomical Brightness
Seeing
Fluence
Design Exercise: Telescope Specifications
1.6 Questions and Problems
References
Chapter 2 Sources of Aberrations
2.1 Atmospheric Turbulence
2.1.1 Refractivity
2.1.2 Statistical Representations
2.1.3 Refractive index structure constant
2.1.4 Turbulence effects
2.1.4.1 Fried’s coherence length
2.1.4.2 Scintillation
2.1.4.3 Beam wander or tilt
2.1.4.4 Higher-order phase variation
2.1.4.5 Phase Tears and Branch Points
2.1.5 Turbulence MTF
2.1.6 Multiple layers of turbulence
2.2 Marine Environments
2.2.1 The Marine Layer
2.2.2 Underwater Effects
2.3 Thermal Blooming
2.3.1 Blooming strength and critical power
2.3.2 Turbulence, jitter, and thermal blooming
2.4 Aero-Optics
2.5 Non-atmospheric Sources
2.5.1 Optical misalignments and jitter
2.5.2 Platform Motion
2.5.3 Large optics: segmenting and phasing
2.5.4 Thermally induced distortions of optics
2.5.5 Gravity Sag
2.5.6. Manufacturing and Microerrors
2.5.7 Other sources of aberrations
2.5.8 Aberrations in laser resonators and lasing media
2.5.9 Optical Properties of the Vitreous and Aqueous Humors of the Eye
Design Exercise: Uncompensated Telescope Performance
2.6 Questions and Problems
References
Chapter 3 Adaptive Optics Compensation
3.1 Phase Conjugation
3.2 Limitations of Phase Conjugation
3.2.1 Turbulence tilt/jitter error
3.2.2 Turbulence higher order spatial error
3.2.2.1 Modal analysis
3.2.2.2 Zonal analysis – Corrector fitting error
3.2.3 Turbulence temporal error
3.2.4 Sensor noise limitations
3.2.5 Thermal blooming compensation
3.2.6 Anisoplanatism
3.2.7 Optical Noise – Speckle
3.2.8 Optical Noise - Scattering and Stray Light
3.3 Artificial Guide Stars
3.3.1 Rayleigh guide stars
3.3.2 Sodium guide stars
3.3.3 Lasers for guide stars
3.4 Combining the Limitations
3.5 Linear Analysis
3.5.1 Random wavefronts
3.5.2 Deterministic Wavefronts
3.6 Partial Phase Conjugation
3.7 Modeling
Design Exercise: AO System Requirements Development
3.8 Questions and Problems
References
Chapter 4 Adaptive Optics Applications and Systems
4.1 Imaging Systems
4.1.1 Astronomical imaging systems
4.1.1.1 Single conjugate adaptive optics
4.1.1.2 Multiconjugate adaptive optics
4.1.1.3 Extending the field-of-view with discrete layer-oriented atmospheric correction
4.1.1.4 Extending the field-of-view with continuous distribution (tomographic) atmospheric correction
4.1.1.5 Extreme Adaptive Optics for Extrasolar Planet Imaging
4.1.1.6 Coronagraphs
4.1.1.7 Solar Adaptive Optics
4.1.1.8 Comparison of Astronomical Imaging Systems
4.1.2 Biomedical and retinal imaging
4.1.2.1 Conventional adaptive optics
4.1.2.2 Optical coherence tomography
4.1.2.2.1 Time-domain OCT
4.1.2.2.2 Frequency domain OCT
4.1.2.3 Scanning laser ophthalmology
4.1.2.4 SLO combined with OCT
4.1.3 Microscopy
4.1.4 Metrology
4.1.5 Autonomy and Artificial Intelligence
4.2 Beam Propagation Systems
4.2.1 Target loop systems
4.2.2 Local loop beam cleanup systems
4.2.3 Common Path Common Mode Systems
4.2.4 Beam Combining
4.2.5 Alternative concepts
4.2.6 Pros and cons of the various approaches
4.2.7 Free-space laser communications systems
4.2.7.1 Fading and transmission loss
4.2.7.2 Bit Error Rates
4.2.7.3 Quantum Networking
4.2.7.4 Beamforming for Optical Vortices or Orbital Angular Momentum
4.2.7.5 Optical Time/Frequency Transfer
4.2.8 Horizontal path imaging systems
4.3 Manufacturing
4.4 Unconventional Adaptive Optics
4.4.1 Nonlinear optics
4.4.2 Elastic photon scattering, DFWM
4.4.3 Inelastic photon scattering (Raman and Brillouin scattering)
4.5 System Engineering
4.5.1 System Performance Requirements:
4.5.2 Compensated Beam Properties:
4.5.3 Wavefront Reference Beam Properties:
4.5.4 Optical System Integration:
4.5.5 System Modeling
4.6 Questions and Problems
References
Chapter 5 Wavefront Sensing: Optical and Mechanical Aspects
5.1 Directly Measuring Phase
5.1.1 The non-uniqueness of the diffraction pattern
5.1.2 Determining phase information from intensity
5.1.3 Modal and zonal sensing
5.1.4 Dynamic range of tilt and wavefront measurement
5.2 Direct Wavefront Sensing — Modal
5.2.1 Importance of wavefront tilt
5.2.2 Measurement of tilt
5.2.3 Focus sensing
5.2.4 Modal sensing of higher-order aberrations
5.3 Direct Wavefront Sensing — Zonal
5.3.1 Interferometric wavefront sensing
5.3.1.1 Methods of interference
5.3.1.2 Self-referencing interferometers
5.3.1.3 The principle of the shearing interferometer
5.3.1.4 Practical operation of shearing interferometer
5.3.1.5 Lateral shearing interferometers
5.3.1.6 Rotation and radial shear interferometers
5.3.1.7 Phase shifting interferometers
5.3.2 Shack-Hartmann wavefront sensors
5.3.3 Holographic Wavefront Sensor
5.3.4 Curvature sensing
5.3.5 Pyramid wavefront sensor
5.3.6 Other Approaches
5.3.6.1 Plenoptic Wavefront Sensor
5.3.6.3 Reverse Hartmann WFS
5.3.7 Selecting a method
5.4 Indirect Wavefront Sensing Methods
5.4.1 Multidither adaptive optics
5.4.2 Image sharpening
5.4.3 Full field sensing
5.5 Optical Spatial Filtering
5.6 Wavefront Sampling
5.6.1 Beamsplitters
5.6.2 Hole gratings
5.6.3 Temporal duplexing
5.6.4 Reflective wedges
5.6.5 Diffraction gratings
5.6.6 Hybrids
5.6.7 Sensitivities of sampler concepts
5.7 Questions and Problems
References
Chapter 6 Wavefront Sensing: Detection and Algorithms
6.1 Wavelength Selection
6.2 Detectors
6.2.1 Figures of Merit
6.2.1.1 Responsivity
6.2.1.2 Rise Time
6.2.1.3 Noise Equivalent Power and Angle
6.2.1.4 Detectivity and D*
6.2.2 Noise
6.2.2.1 Quantum Noise
6.2.2.2 Thermal Noise
6.2.2.3 Other Sources of Noise
6.2.2.4 Wavefront Sensor Noise Impact
6.2.2.5 Persistence
6.2.3 Detector Technology
6.2.3.1 Solid State Detectors
6.2.3.1.1 Photovoltaic
6.2.3.1.2 Photoconductive
6.2.3.1.3 Photoemissive Detectors and Photomultipliers
6.2.3.2 Detector Arrays
6.2.3.2.1 CCD
6.2.3.2.2 CMOS
6.2.3.3 Position Sensing Detectors
6.2.3.4 Thermal Detectors
6.3 Algorithms
6.3.1 Spot Finding
6.3.1.1 Centroiding
6.3.1.1.1 Thresholding
6.3.1.1.2 Windowing
6.3.1.2 Correlation
6.3.1.2.1 Spatial Filtering
6.3.1.2.2 Matched Filter
6.3.1.2.3 Correlation Tracker for Extended Sources
6.3.1.3 Nonlinear Curve Fitting
6.3.1.4 Detector Quality Factor
6.3.2 Phase diversity
6.3.3 Deconvolution
6.3.4 Gerchberg-Saxton Algorithms
6.3.5 Machine Learning
6.4 Questions and Problems
References
Chapter 7 Wavefront Correction
7.1 Wavefront Correction Requirements
7.2 Actuator Types
7.2.1 Ferroelectric Actuators
7.2.1.1 Electrostriction
7.2.1.2 Converse Piezoelectric Effect
7.2.1.3 Fabrication
7.2.1.4 Comparison of Electrostrictive and Piezoelectric Actuators
7.2.2 Lorentz Force Actuators
7.2.3 Electrostatic Actuators
7.2.4 Magnetostrictive Actuators
7.2.5 Alternative Actuators
7.2.6 Comparison of Actuators by Performance Indices
7.3 Modal Tilt Correction
7.4 Modal Higher-Order Correction
7.5 Deformable Mirrors
7.5.1 Segmented Mirrors
7.5.2 Surface Normal Mirrors
7.5.3 Surface Parallel and Edge Actuated Mirrors
7.5.4 Monolithic Mirrors
7.5.5 Membrane and Micromachined Mirrors
7.5.6 Actuator influence functions
7.5.7 Large and multiple deformable mirrors
7.5.8 Bimorph, Unimorph, and Multimorph Corrector Mirrors
7.5.9 Comparison of Deformable Mirror Technologies
7.6 Large Correcting Optics
7.7 Special Correction Devices
7.7.1 Liquid crystal phase modulators
7.7.2 Spatial Light Modulators
7.7.3 Metasurfaces
7.7.4 Fluidic deformable mirrors
7.7.5 Multiple lens correctors
7.8 Electronic Driver Systems
7.9 Questions and Problems
References
Chapter 8 Control Theory
8.1 Introduction
8.2 Classical Single-Channel Linear Control
8.2.1 Laplace Transforms
8.2.2 Transfer functions
8.2.3 Partial Fraction Expansions
8.2.4 Proportional control
8.2.5 First- and second-order response
8.2.6 Feedback
8.2.7 Frequency response of control systems
8.2.8 State Space Representations
8.2.9 Stability
8.2.10 Observability and Controllability
8.2.11 Noise and Uncertainty
8.2.12 High Speed Systems
8.3 Discrete and Sampled Data Control Systems
8.3.1 Sampling Impact on Stability
8.3.2 Sampled Data and Latency
8.3.3 Quantization
8.4 Multivariable Control Systems
8.4.1 Vector and Matrix Norms
8.4.2 Singular Values and Principal Directions
8.5 Linear Quadratic Optimal Control Theory
8.5.1 Cost Functions
8.5.2 Linear Quadratic Regulator Controller Design
8.5.3 Observers, Estimators and the Separation Principle
8.5.4 Optimal State Estimation
8.5.4.1 Wiener Filter
8.5.4.1 Kalman Filter
8.5.5 Linear Quadratic Gaussian and Tracking Controller Design
8.6 Robust Control Theory
8.6.1 Uncertainty
8.6.2 Generalized Control Problem
8.6.3 H2 Control
8.6.4 H¥ Control
8.7 Adaptive Controls
8.7.1 Adaptive Control Approaches
8.7.2 Machine Learning
8.8 Questions and Problems
References
Chapter 9 Wavefront Reconstruction and Control
9.1 Introduction
9.2 Adaptive Optics System Geometry
9.2.1 Path A: Direct Zonal Reconstruction, Phase from Wavefront Slopes
9.2.2 Path B: Direct Modal Reconstruction, Modes from Wavefront Slopes
9.2.3 Path C: Direct Zonal Reconstruction, Phase from Wavefront Modes
9.2.4 Path D: Direct Modal Reconstruction, Modes from Wavefront Modes
9.2.5 Path E: Zonal Corrector from Continuous Zonal Phase
9.2.6 Path F: Modal Corrector from Continuous Zonal Phase
9.2.7 Path G: Zonal corrector from Modal Phase
9.2.8 Path H: Modal Correctors from Modal Phase
9.2.9 Path I: Indirect Modal Corrector from Wavefront Modes
9.2.10 Path J: Indirect Zonal Corrector from Wavefront Slopes
9.3 Inverse Problems and Wavefront Reconstruction
9.3.1 Least-Squares Methods
9.3.2 Regularization
9.3.3 Reconstruction Errors
9.3.4 Linear Estimation
9.3.5 Piston Suppression
9.3.6 Poke (Geometry) Matrix Calibration
9.3.6.1 Tip/Tilt Removal
9.3.6.2 Piston Removal
9.3.6.3 Waffle Removal
9.3.6.4 Calibrated Poke (Geometry) Matrix
9.3.6.5 Poke Matrix Smoothing
9.3.7 Modal Filtering
9.3.7.1 Local Curvature Filtering
9.3.7.2 Local Waffle Filtering
9.3.7.3 Nullspace Filtering
9.3.7.4 Turbulence Conditioning
9.3.7.5 Combining Weighting Matrices
9.3.8 Numerical Spatial Filtering
9.3.9 Slope Discrepancy
9.3.10 Branch Point Tolerant Reconstructors
9.3.11 Computationally Efficient Techniques
9.3.11.1 Stationary Iterative Methods
9.3.11.2 Conjugate Gradient Methods
9.3.11.3 Landweber Iteration
9.3.11.4 Sparse Matrix Methods
9.3.11.5 Fourier Transform Control
9.3.11.6 Other Methods
9.3.12 Target in the Loop Methods
9.4 Modal Feedback
9.5 Predictive Control
9.5.1 Predictive Fourier Control
9.5.2 Empirical Orthogonal Functions
9.6 Offloads for Woofer-Tweeter Systems
9.7 Computational Architectures
9.8 Dynamical System Models
9.8.1 Wavefront Sensor
9.8.2 Deformable Mirror
9.8.3 Controller
9.8.3.1 Leaky Integrator Controllers
9.8.3.2 Minimum Variance Controllers
9.8.3.3 Adaptive Controllers
9.8.3.4 Bandwidth Estimation
9.9 Primary and Replica Configurations
9.9.1 Actuator and Subaperture Observability
9.9.2 Replica Logic for the Reconstructor
9.9.3 Replica Logic for the Modal Feedback Matrix
9.10 Specific Issues and Concerns
9.10.1 Misregistration
9.10.2 Speckle Noise and ExAO Specific Concerns
9.10.3 MCAO Specific Concerns
9.10.4 Pyramid Sensor Specific Concerns
9.10.5 Scaling Laws
9.11 Applications to Post-processing
9.12 Wavefront Shaping
9.13 Questions and Problems
References
Biography
Robert K. Tyson is a professor emeritus of physics and optical science at the University of North Carolina at Charlotte (UNC Charlotte) and a fellow of the International Society for Optics and Photonics (SPIE).
Benjamin Frazier is a Senior Sensor Systems Engineer at the Johns Hopkins University Applied Physics Laboratory (JHU/APL).
