This book explores the possibility of using azimuthal Walsh filters as an effective tool for manipulating far-field diffraction characteristics near the focal plane of rotationally symmetric imaging systems. It discusses the generation and synthesis of azimuthal Walsh filters, and explores the inherent self-similarity presented in various orders of these filters, classifying them into self-similar groups and sub-groups. Further, it demonstrates that azimuthal Walsh filters possess a unique rotational self-similarity exhibited among adjacent orders. Serving as an atlas of diffraction phenomena with pupil functions represented by azimuthal Walsh filters of different orders, this book describes how orthogonality and self-similarity of these filters could be harnessed to sculpture 2D and 3D light distributions near the focus.

Autorentext

Dr. Indrani Bhattacharya is a Post-doctoral researcher associated with Prof. Ayan Banerjee of Light Matter Interaction Lab, Indian Institute of Science Education and Research, IISER, Kolkata and Prof. Vasudevan Lakshminarayanan of School of Optometry, University of Waterloo, Canada. She obtained her Ph.D. from the Department of Applied Optics and Photonics, University of Calcutta. Dr. Bhattacharya is having 20 years industry and 9 years of academic experience. Her research areas include Diffractive Optics, Biomimetics, Optical Tweezers, Point Spread Function Engineering, In-Vivo and In-Vitro Biomedical Applications, Optical Fibre Sensors. She is a member of Optical Society of India, International Society of Optics and Photonics, International Society of Optomechatronics. Prof. Lakshminarayan Hazra has over four decades of academic and industrial experience. He is an Emeritus Professor and Former Head of the Department of Applied Optics and Photonics at the University of Calcutta, Kolkata, India. His areas of professional specialization include lens design/optical system design, image formation & aberration theory, diffractive optics, and optical and photonic instrumentation. He is a Fellow of the Optical Society of America, and the International Society for Optics and Photonics (SPIE). He is the Editor-in-Chief of the archival journal, Journal of Optics, (Springer) in collaboration with the Optical Society of India.

Inhalt

1. Introduction

2. Walsh Functions, Walsh Filters And Self-Similarity

2.1 Introduction

2.2 One Dimensional Walsh Functions

2.3 Two Dimensional Walsh Functions

2.3.1 Rectangular Walsh Functions

2.3.2 Polar Walsh Functions

2.4 Radial Walsh Functions

2.5 Azimuthal Walsh Functions 2.6 Self-Similarity In Azimuthal Walsh Functions

2.7 Walsh Filters

2.7.1 Radial Walsh Filters

2.7.2 Azimuthal Walsh Filters

2.8 Self-Similarity In Azimuthal Walsh Functions

References

3. Transverse Intensity Distribution On The Far-field Plane Of Azimuthal Walsh Filters

3.1 Introduction

3.2 Analytical Formulation of Far-field Amplitude Distribution along an azimuth for a Single Sector on the Exit Pupil

3.3 Azimuthal Walsh Filters on the Exit Pupil

3.4 Asymmetrical amplitude point spread function on the Far-field Plane due to azimuthal Walsh filter at the Exit Pupil Plane

3.4.1 Case 1 : Zero Order Azimuthal Walsh Filter

3.4.2 Case 2 : First Order Azimuthal Walsh Filter

3.4.3 Case 3 : Second Order Azimuthal Walsh Filter

3.4.4 Case 4 : Third Order Azimuthal Walsh Filter

3.5 Intensity Distribution on the Far-Field Plane

References

4. Self-Similarity in Transverse Intensity Distributions on the Far-Field Plane of Self-Similar Azimuthal Walsh Filter

4.1 Introduction

4.2 Transverse Intensity Distributions for Zero Order Azimuthal Walsh Filter on the Far-Field Plane

4.3 Self-Similarity in Far-Field intensity distributions for Group I Self-Similar members of Azimuthal Walsh Filters

4.4 Self-Similarity in Far-Field intensity distributions for Group IIA Self-Similar members of Azimuthal Walsh Filters

4.5 Self-Similarity in Far-Field intensity distributions for Group IIB Self-Similar members of Azimuthal Walsh Filters

4.6 Self-Similarity in Far-Field intensity distributions for Group IIIA Self-Similar members of Azimuthal Walsh Filters

4.7 Rotational Self-Similarity observed in 2D Transverse intensity distributions at Far-Field Plane for adjacent orders of Azimuthal Walsh Filters

References

5. Intensity Distribution In The Far-field Region of Azimuthal Walsh Filters

5.1 Introduction

5.2 Analytical Formulation of Intensity distribution on axially shifted image planes

5.2.1 Synthesis of Azimuthal Walsh Filters using Azimuthal Walsh Block functions

5.2.2 Evaluation of integral using the concept of concentric equal area zones of Azimuthal Walsh Filters

5.3 Illustrative Results with Discussion

5.3.1 Intensity distribution in the Far-Field region for Zero Order azimuthal Walsh Filters

5.3.2 Intensity distribution in the Far-Field region for First Order azimuthal Walsh Filters

5.3.3 Intensity distribution in the Far-Field region for Second Order azimuthal Walsh Filters 5.3.4 Intensity distribution in the Far-Field region for Third Order azimuthal Walsh Filters

5.3.5 Intensity distribution in the Far-Field region for Fourth Order azimuthal Walsh Filters 5.3.6 Intensity distribution in the Far-Field region for Fifth Order azimuthal Walsh Filters

5.3.7 Intensity distribution in the Far-Field region for Sixth Order azimuthal Walsh Filters 5.3.8 Intensity distribution in the Far-Field region for Seventh Order azimuthal Walsh Filters

5.4 Intensity Distributions on Transverse Planes Very Near to the Focus With Azimuthal Walsh Filters 5.4.1 Intensity Distribution in the Immediate Vicinity of the Far-Field Plane

for First Order Azimuthal Walsh Filters

5.4.2 Intensity Distribution in the Immediate Vicinity of the Far-Field Plane  for Second Order Azimuthal Walsh Filters

5.4.3 Intensity Distribution in the Immediate Vicinity of the Far-Field Plane  for Third Order Azimuthal Walsh Filters

5.4.4 Intensity Distribution in the Immediate Vicinity of the Far-Field Plane  for Fourth Order Azimuthal Walsh Filters 5.4.5 Intensity Distribution in the Immedia...