Advances In Speckle Metrology And Related Techniques

Speckle metrology includes various optical techniques that are based on the speckle fields generated by reflection from a rough surface or by transmission through a rough diffuser. These techniques have proven to be very useful in testing different materials in a non-destructive way. They have changed dramatically during the last years due to the development of modern optical components, with faster and more powerful digital computers, and novel data processing approaches.

This most up-to-date overview of the topic describes new techniques developed in the field of speckle metrology over the last decade, as well as applications to experimental mechanics, material science, optical testing, and fringe analysis.

Prof. Guillermo H. Kaufmann is professor of Applied Optics at the National University of Rosario, Argentina, and chief scientist at the Physics Institute of Rosario which is linked both to the university and to the National Council of Scientific and Technological Research. He is also the director of the French-Argentine International Centre for Information and Systems Sciences. He has worked as a visiting researcher at the National Physical Laboratory, UK, the University of Michigan, and Loughborough University. Professor Kaufmann has co-authored more than 170 papers published in international journals and conference proceedings and several book chapters. He is a fellow member of both SPIE and the Optical Society of America. In 2003 the Secretary of Science and Technology of Argentina awarded him the Bernardo Houssay Prize for his contributions to the field of optical engineering.

Preface.

List of Contributors.

1 Radial Speckle Interferometry and Applications (Armando Albertazzi Gonçalves Jr. and Matías R. Viotti).

1.1 Introduction.

1.2 Out-of-Plane Radial Measurement.

1.2.1 Radial Deformation Measurement of Short Internal Cylinders.

1.2.2 Radial Deformation Measurement of Long Internal Cylinders.

1.2.3 Radial Deformation Measurement of External Cylinders.

1.3 In-Plane Measurement.

1.3.1 Configuration Using Conical Mirrors.

1.3.2 Configuration Using a Diffractive Optical Element.

1.4 Applications.

1.4.1 Translation and Mechanical Stress Measurements.

1.4.2 Residual Stress Measurement.

1.5 Conclusions.

References.

2 Depth-Resolved Displacement Field Measurement (Jonathan M. Huntley and Pablo D. Ruiz).

2.1 Introduction.

2.2 Low-Coherence Electronic Speckle Pattern Interferometry.

2.3 Wavelength Scanning Interferometry.

2.3.1 WSI with a Single Scattering Surface.

2.3.1.1 Fourier Transform for Measurement of Optical Path Length.

2.3.1.2 Fourier Transform for Calculation of Interference Phase.

2.3.1.3 Range and Resolution of Optical Path Difference Measurement.

2.3.1.4 Determination of Scattering Point Location.

2.3.1.5 Gauge Volume and Displacement Sensitivity.

2.3.2 WSI with Volume Scatterers.

2.3.2.1 Proof-of-Principle Experiments: Two Scattering Layers.

2.3.3 Comparison of WSI with LCSI.

2.4 Spectral Optical Coherence Tomography.

2.4.1 Phase Contrast SOCT for 2D Out-of-Plane Displacement Field Measurement.

2.4.2 PC-SOCT for 2D In-Plane and Out-of-Plane Displacement Field Measurement.

2.4.3 Hyperspectral Interferometry for 3D Surface Profilometry.

2.5 Tilt Scanning Interferometry.

2.5.1 Depth-Dependent Phase Shift Introduced by a Tilting Wavefront.

2.5.2 Extraction of the Scattered Amplitude Distribution.

2.5.3 Depth-Resolved Displacements.

2.5.4 Gauge Volume, Depth Range, and Displacement Sensitivity.

2.5.5 Experimental Implementation.

2.6 Depth-Resolved Techniques Viewed as Linear Filtering Operations.

2.6.1 Methods Viewed as Linear Filtering Operations.

2.6.2 Relationship Between W(K) and Spatial Resolution.

2.6.3 Relationship Between W(K) and Displacement Sensitivity.

2.6.4 Ewald Sphere for a Wavelength Scanning Interferometer.

2.6.5 Ewald Sphere for a Tilt Scanning Interferometer.

2.6.6 Comparison of Spatial Resolution for WSI and TSI.

2.7 Phase Unwrapping in Three Dimensions.

2.7.1 Phase Singularities in Two-Dimensional Phase Data.

2.7.2 Phase Singularity Loops in Three-Dimensional Phase Data.

2.7.3 3D Phase Unwrapping Algorithm.

2.7.4 Remaining Ambiguities.

2.7.5 Example: Dynamic Deformation of Carbon-Fiber Composite Panel.

2.8 Concluding Remarks.

References.

3 Single-Image Interferogram Demodulation (Manuel Servin, Julio Estrada, and Antonio Quiroga).

3.1 Introduction.

3.1.1 Spatial Carrier Frequency Techniques.

3.1.2 Spatial Demodulation Without Carrier.

3.2 The Fourier Spatial Demodulating Method.

3.3 Linear Spatial Phase Shifting.

3.4 Nonlinear Spatial Phase Shifting.

3.5 Regularized Phase Tracking.

3.6 Local Adaptive Robust Quadrature Filters.

3.7 Single Interferogram Demodulation Using Fringe Orientation.

3.7.1 Orientation in Interferogram Processing.

3.7.2 Fringe Orientation and Fringe Direction.

3.7.3 Orientation Computation.

3.7.3.1 Gradient-Based Orientation Computation.

3.7.3.2 Plane Fit Orientation Calculation.

3.7.3.3 Minimum Directional Derivative.

3.7.4 Direction Computation.

3.7.4.1 Regularized Phase Tracking Direction Estimation.

3.7.4.2 Vector Field-Regularized Direction Estimation.

3.8 Quadrature Operators.

3.8.1 Phase Demodulation of 1D Interferograms.

3.8.2 Phase Demodulation from a Single Interferogram: the Vortex Transform.

3.8.3 Vortex Transform-Based Orientation Computation.

3.8.4 The General n-Dimensional Quadrature Transform.

3.9 2D Steering of 1D Phase Shifting Algorithms.

3.10 Conclusions.

References.

4 Phase Evaluation in Temporal Speckle Pattern Interferometry Using Time–Frequency Methods (Alejandro Federico and Guillermo H. Kaufmann).

4.1 Introduction.

4.2 The Temporal Speckle Pattern Interferometry Signal.

4.3 The Temporal Fourier Transform Method.

4.4 Time–Frequency Representations of the TSPI Signals.

4.4.1 Preliminaries.

4.4.1.1 The Asymptotic Signal and the Exponential Model.

4.4.1.2 Fidelity Measures.

4.4.2 The Windowed Fourier Transform.

4.4.3 The Wavelet Transform.

4.4.3.1 Evaluation of the Ridge of a Wavelet Transform.

4.4.3.2 Applications of the Morlet Transform Analysis in TSPI and Other Related Techniques.

4.4.3.3 The Chirped Wavelet Transform.

4.4.3.4 Other Wavelet Transforms.

4.4.4 The Quadratic Time–Frequency Distribution.

4.4.5 The Empirical Mode Decomposition and the Hilbert Transform.

4.4.5.1 The Empirical Mode Decomposition Method.

4.4.5.2 The Hilbert Transform.

4.4.6 The Generalized S-Transform.

4.4.7 Two- and Three-Dimensional Approaches.

4.4.7.1 The Windowed Fourier Transform Method.

4.4.7.2 Wavelet Transform Methods.

4.5 Concluding Remarks.

References.

5 Optical Vortex Metrology (Wei Wang, Steen G. Hanson, and Mitsuo Takeda).

5.1 Introduction.

5.2 Speckle and Optical Vortices.

5.3 Core Structure of Optical Vortices.

5.4 Principle of Optical Vortex Metrology.

5.4.1 Complex Signal Representation of a Speckle-Like Pattern.

5.4.2 Principle of Optical Vortex Metrology.

5.5 Some Applications.

5.5.1 Nanometric Displacement Measurement.

5.5.2 Linear and Angular Encoder.

5.5.3 Fluid Mechanical Analysis.

5.5.4 Biological Kinematic Analysis.

5.6 Conclusion.

References.

6 Speckle Coding for Optical and Digital Data Security Applications (Arvind Kumar, Madan Singh, and Kehar Singh).

6.1 Introduction.

6.2 Double Random Fourier Plane Encoding.

6.2.1 Influence of Coded Image Perturbations, Noise Robustness, and SNR.

6.3 Variants of the DRPE and Various Other Encryption Techniques.

6.3.1 Fresnel and Fractional Fourier Transform Domain Encoding.

6.3.2 Color Image Encoding and Digital Simulation/Virtual Optics-Based Techniques.

6.3.3 Phase Retrieval- and Polarization-Based Techniques.

6.3.4 Interference and Joint Transform Correlator Architecture-Based Techniques.

6.3.5 Fully Phase Encryption Techniques and Encrypted Holographic Memory.

6.4 Attacks against Random Encoding.

6.5 Speckle Coding for Optical and Digital Data Security.

6.6 Encryption Using a Sandwich Phase Mask Made of Normal Speckle Patterns.

6.6.1 Theoretical Analysis.

6.6.2 Description of the Experimental Work.

6.6.2.1 Preparation of Speckle Phase Masks.

6.6.2.2 Making a Sandwich Phase Mask.

6.6.2.3 Technique for Easy Alignment of the Constituent Speckle Phase Masks.

6.6.2.4 Experimental Results.

6.6.2.5 Computer Simulation.

6.7 Optical Encryption Using a Sandwich Phase Mask Made of Elongated Speckle Patterns.

6.7.1 Preparation of the Elongated Speckle Phase Mask.

6.7.2 Description of the Method.

6.7.3 Computer Simulation Results.

6.8 Speckles for Multiplexing in Encryption and Decryption.

6.9 Multiplexing in Encryption Using Apertures in the FT Plane.

6.9.1 Methodology.

6.9.2 Computer Simulation.

6.9.3 Effect of Aperture Size on the Encryption and Decryption.

6.9.4 Effect of Increasing the Number and Size of the Apertures.

6.9.5 Multiplexing in Encryption Using Circular Apertures.

6.9.6 Multiplexing in Encryption Using Square Apertures.

6.10 Multiplexing by In-Plane Rotation of Sandwich Phase Diffuser and Aperture Systems.

6.10.1 Methodology.

6.10.2 Effect on Decrypted Images of Rotation of One of the Constituent Phase Diffusers.

6.10.3 Multiplexing in Encryption Using the Rotation of the RPM Rsm.

6.10.4 Multiplexing by Using Set of Apertures and Angular Rotation of Rsm.

6.11 Speckles in Digital Fresnel Field Encryption.

6.11.1 Digital Recording and Numerical Reconstruction of an Off-Axis Fresnel Hologram.

6.11.2 Digital Fresnel Field Encryption.

6.11.2.1 Digital Encryption of Fresnel Field Using Single Random Phase Encoding.

6.11.2.2 Direct Decryption of 3D Object Information from Encrypted Fresnel Field.

6.11.3 Experiment.

6.11.4 Results and Discussion.

6.11.4.1 Discussion of Encryption and Decryption by the Proposed Method.

6.11.4.2 Some General Remarks on Digital Encryption of Holographic Information.

6.12 Conclusions.

References.

Index.