Books by Dr. Andrew Motes

This page describes many of the books written by Dr. Andrew (Andy) Motes. Many of these books are available in Kindle format through Amazon or in PDF format through Dr. Motes. You may leave comments and questions about these books here on the AM Photonics Home page, or you can click the following button to take you to Dr. Motes' Facebook page and leave comments there.

Click the following button to go to Dr. Motes' Amazon author page.

## Ray Man: A Sharecropper's Memoir

"Hardships create character in people like heat and pressure create diamonds in carbon." This book describes the extraordinary journey of transformation for Dr. Andrew Motes from a life of poverty in the backwoods of Arkansas to becoming one of the World's leading experts for laser technology--from studying by kerosene lamp to designing space-age technology. The author uses a story-telling style to describe his experiences as a sharecropper, trapper, grocery-store clerk, motorcycle mechanic, electronic technician, electronic engineer, military officer, computer software developer, space systems engineer or "rocket scientist", laboratory research scientist, laser physicist, college professor, civil servant, and defense contractor. His journey of transformation was also a journey of understanding--of himself and humanity. In his many roles he interacted with people at all social levels and learned that all of mankind suffers from one common affliction, regardless of social status. $6.99 Kindle.

## The River Calls Your Name

In 1981 two young backpackers/fishermen struggle for survival in the rugged mountains of Utah against both man and beast. Alone, trapped, and unarmed their only hope is a supernatural event. This is the perfect book for young adults searching for adventure, encouragement, and the meaning of life. An exciting but thought provoking book. (Fiction) $2.99

## Digital-Computer-Based Simulations

for Beginners

Engineers and physicists find it useful to model physical systems using digital computers. This book teaches the basic concepts of computer modeling using a variety of examples that include: mechanical systems, electrical systems, satellite orbit simulations, aircraft flight simulators, thermal diffusion simulations, and laser beam propagation simulations. Most of my code is available to readers upon request. I think that this is one of my best technical books. $9.99

**Table of Contents:**

Preface

Introduction

Analog Computer Simulations—A History Lesson

Discrete/Digital Approximations of Analog Signals

Discrete Integrators

Time-Dependent Simulations

Mechanical System Simulations

Electrical System Simulations

Passive Electrical Circuit Simulations

Field-Effect Transistor Amplifier Simulations

Space-Flight Simulations

Orbit Tracks

Including Atmospheric Drag for Low-Earth Orbits

A Three-dimensional Orbit Simulator

Aircraft Flight Simulations

Coordinate Frames

Euler Angles

Aircraft Control Surfaces

Nomenclature

6-Degree of Freedom (6DOF) Model

Calculating Force and Moment Inputs

The Aircraft Computer Model

Inertial Navigation Systems

Thermal Diffusion using the Finite-Difference Method

Derivation

Transparent Boundary Conditions

Including Radiation Loss

Time-Independent Simulations

Finite-Difference Laser Beam Propagation Method

Derivation

Simulation Results

Including Turbulence

Fast Fourier Transform Laser Beam Propagation Method

Derivation

Example Simulation

Including Turbulence

Harmonic-Expansion Wave Propagation Method

Derivation

Example Simulations

Including Focus

Optical Waveguide Simulations

Final Comments

Appendix A, The Time-Independent, Paraxial Wave Equation

The Helmholtz Equation

The Paraxial Approximation

Appendix B, Imaginary Numbers and Complex Math

Waves

The Imaginary Number Unit

Phasor Notation

Intensity

Appendix C, an Atmospheric Turbulence Model

References

## Physics of Flight

An Introduction

If you've ever wanted to learn how aircraft fly but didn't want to take an engineering graduate-level course in flight dynamics, this is the book you should read. It is part of a series of short, inexpensive technical books designed for non-engineers or engineering students. With this book you'll learn how to design your own computer flight simulator and will have access to the author's own FlightSim computer code for Visual Studio 2010. $4.99.

## Space Flight

For Beginners

You don't have to be a rocket scientist to understand rocket science. This book shows how easy it is to understand space flight and orbital mechanics. In this book you'll learn how gravitational and centripetal forces cancel to enable orbits. You'll learn how orbits are classified and how to do orbital transfers. You'll even learn to do space mission design for interplanetary missions. You'll be surprised how easy it really is. It comes with software for simulating orbits. $5.99

## Imaginary Numbers

and Their Roles in Engineering and Physics

The concept of imaginary numbers and complex math can be difficult for some engineers and physicists. On the other hand, they are extremely useful for solving many types of equations that engineers and physicists encounter. The goal of this book is to demystify imaginary numbers and describe how they are used in multiple technical disciplines. $4.99.

## Field-Effect Transistor Amp

Analysis and Design

Learn how to design field-effect transistor amplifiers without the hassle of also learning about the physics. This is an introduction to the subject and comes with free software for doing the mathematics--internet links for software download are in the text. $4.99

## Solar and Wind Power

The Basics

Want to understand the basics of solar and wind energy before you build your own system? If so, this is the book you need. You'll learn the difference between energy and power, how voltage is related to current and power, and how current is related to voltage and resistance. You'll learn about all the different parts of an alternative energy system, what their purpose is, and how they are wired. You'll also lean how to calculate the size system you need. If you already have the knack for these things, this may be the only book you'll need. $4.99.

## Basic

**Laser Weapon System Design**

This electronic book describes the design process for laser weapons and shows how power and weight are related to laser efficiency and duty cycle. The author uses example requirements to step the reader through a basic design. It was written for engineers or physicists who have no experience in the field, or for engineering students who are interested in learning about laser weapons. Readers are expected to have an understanding of optics and laser physics. This book can also be used as a teaching tool for the engineering design process. $7.99.

## A Student's Guide to

**Fiber Lasers**

(with Solutions in Mathcad)

This electronic book provides graduate students in Physics or Optical Engineering with a jump start in their fiber laser research. The author references nearly 200 books and papers in this document. You'll learn about step-index fibers, micro-structured fibers (photonic crystal, multi-core, leaky channel, etc.). You'll learn how to calculate modes for the step-index and how to determine stability for micro-structured fibers. You'll learn about optical waveguides and how these are converted to fiber lasers, both continuous-wave and pulsed. Finally, the text has web links so you can download all the Mathcad code used by the author. $9.99.

**Table of Contents:**

1 Introduction. 1

2 Optical Waveguides. 2

2.1 Light Confinement in Optical Waveguides by Total Internal Reflection. 2

2.2 Transverse Modes in Optical Waveguides. 7

2.2.1 Planar Waveguide Mode Derivation Using Ray Optics. 7

2.2.2 Planar Waveguide Mode Derivation Using Maxwell’s Equations. 11

2.2.3 Cylindrical Waveguide Mode Derivation Using Maxwell’s Equations. 18

2.3 Summary. 25

2.4 Practice Problems. 27

3 Optical Fiber Design and Fabrication. 29

3.1 Dual-Clad Fibers. 29

3.2 Large Mode Area Fibers. 30

3.2.1 LMA Fibers and Bend Loss. 30

3.2.2 Bend-Resistant LMA Fibers. 33

3.3 Polarization-Maintaining Fibers. 35

3.4 Holey Fibers. 37

3.4.1 Solid-Core Photonic Crystal Fibers. 38

3.5 Other Novel Fiber Designs 42

3.5.1 Hollow-Core Photonic Crystal Fibers. 42

3.5.2 Fiber Rod Lasers. 43

3.5.3 Multi-core Fibers. 43

3.5.4 Fibers with Large Flattened Modes. 47

3.5.5 Helical Core Fibers. 49

3.6 Non-Silica-Based Glass Fibers. 51

3.6.1 Phosphate Glass Fibers. 51

3.6.2 Chalcogenide Glass Fibers. 51

3.6.3 Fluorozirconate Glass (ZBLAN) Fibers. 52

3.7 Glass Fiber Fabrication. 53

3.8 Summary. 54

3.9 Practice Problems. 56

4 Fiber Lasers. 57

4.1 The Fiber Laser Oscillator 57

4.1.1 Fiber Cavity, Gain Medium, and Resonator 57

4.1.2 Longitudinal Cavity Modes. 58

4.2 Fiber Laser and Amplifier Pumping Techniques. 60

4.2.1 Fiber End-Pumping. 63

4.2.2 Fiber Side-Pumping. 65

4.3 Mode/Core Overlap Factor 66

4.4 Quantum, Slope, and Wall-Plug Efficiencies. 67

4.5 Rate Equations. 68

4.6 Optical Gain. 72

4.7 Fiber Laser Output Power Calculations. 76

4.8 Rare-Earth Ion-Doped Fiber Lasers and Amplifiers. 79

4.8.1 Neodymium.. 79

4.8.2 Ytterbium.. 79

4.8.3 Erbium-Ytterbium Co-Doping. 82

4.8.4 Directly-Pumped Erbium.. 83

4.8.5 Thulium.. 83

4.9 Summary. 86

4.10 Practice Problems. 89

5 Mechanisms That Limit Fiber Laser and Amplifier Power 91

5.1 Fiber Damage Mechanisms. 91

5.2 Fiber Nonlinear Effects. 93

5.2.1 Stimulated Brillouin Scattering. 93

5.2.2 Stimulated Raman Scattering (SRS) 102

5.3 Limitations Due to Photo Darkening. 103

5.4 Summary. 103

5.5 Practice Problems. 104

6 Pulsed Fiber Lasers. 106

6.1 Methods for Producing Pulses on Laser Outputs. 106

6.1.1 Q-switching. 107

6.1.2 Mode-locking. 108

6.1.3 Amplified Seed Pulse. 111

6.2 Nonlinear Effects in Pulsed Fiber Lasers. 111

6.2.1 SBS & SRS. 111

6.2.2 Four-wave Mixing. 112

6.2.3 Self-Phase Modulation. 112

6.2.4 Self-Focusing. 115

6.3 Group Velocity Dispersion. 115

6.4 Pulse Compression. 121

6.4.1 Pulse Compression with External Gratings. 121

6.4.2 Pulse Compression in all Fiber Ring Lasers. 122

6.5 Some Pulse Energy Limitations and Solutions. 123

6.5.1 ASE Self-Saturation. 123

6.5.2 Glass Damage. 125

6.6 Summary. 125

6.7 Practice Problems. 127

7 Authors Final Comments. 129

Other Books by Dr. Motes. 130

References. 136

## Laser Beam Combining Methods

There are several reasons why combining laser beams is advantageous: (1) some lasers, such as fiber lasers, have good beam quality but limited output power, (2) it allows for graceful degradation, (3) it makes the overall system more modular, and (4) it distributes the cooling load. This electronic book summarizes and describes all the known methods for combining laser beams from low-power lasers into one high-power beam on target. $9.99.

**Table of Contents:**

1 Introduction

2 Definitions

3 Coherent Beam Combining

3.1 Active Coherent Beam Combining

3.1.1 Coherent Beam Combining with a Master Oscillator Power Amplifier

3.1.2 Coherent Beam Combining with a Re-Imaging Waveguide

3.1.3 Coherent Beam Combining using Fiber-Mode-Coupling

3.1.4 Coherent Beam Combining using a Diffractive Optical Element

3.1.5 Coherent Beam Combining using Polarization

3.2 Passive Coherent Beam Combining

3.2.1 Fiber Ring Beam Combining

3.2.2 Self-Fourier Cavity Beam Combination

3.2.3 Coherent Beam Combining using Intra-cavity Coherent Addition

4 Incoherent Beam Combining

4.1 Tiled-array Incoherent Beam Combiners

4.2 Fiber Incoherent Beam Combiners

4.3 Spectral Beam Combining

4.3.1 Spectral Beam Combining with Diffraction Gratings

4.3.2 Spectral Beam Combining with Volume Bragg Gratings

5 Simultaneous Passive Coherent and Spectral Beam Combining

6 Final Comments

References

## Every Engineer Should Know This!

Ever wonder why the guy who barely made it through engineering school is now your boss? Are you really cut out to be a great engineer? What's the difference between an engineer and a great engineer? There are some things they don't teach you in engineering school and it takes many years of experience to learn them. This author gives you the benefit of his 35 years of experience and saves you the trouble of having to learn these lessons the hard way. Written in conversational English, this book is both informative and entertaining. This book is only available in Kindle format. $6.99.

## Fourier Optics

**for the age of Lasers and Computers**

Description:

Fourier optics provides a fast and easy way to find the target irradiance produced by any laser, assuming that the beam is propagating in non-turbulent air or vacuum. This electronic book provides you with all the tools you need for understanding wave optics using the Huygens-Fresnel integral, plus the Fresnel and Fraunhofer approximations--all for quickly finding target irradiance. Written in conversational English, the text has links to all the Mathcad code Dr. Motes used in writing the book, including his Fourier optics toolkit. It also has links to other useful information on the web. $5.99.

Fourier optics provides a fast and easy way to find the target irradiance produced by any laser, assuming that the beam is propagating in non-turbulent air or vacuum. This electronic book provides you with all the tools you need for understanding wave optics using the Huygens-Fresnel integral, plus the Fresnel and Fraunhofer approximations--all for quickly finding target irradiance. Written in conversational English, the text has links to all the Mathcad code Dr. Motes used in writing the book, including his Fourier optics toolkit. It also has links to other useful information on the web. $5.99.

## Free-space Laser Communications:

An Introduction

Learn how optical communications works--both ground-based and space-based. Learn how to do link budgets and how to reduce the effects of atmospheric turbulence. Learn how these systems do signal acquisition and tracking and how to calculate bit error rate. This is the first book you should read on this subject. It's written in plain English with simple explanations. $6.99

## Understanding and Simulating

Free-space Laser Beam Propagation

(with Solutions in Mathcad)

This is an introductory book on laser beam propagation modeling and simulation (in cases where the beam is not confined to a waveguide), and the mathematics for target irradiance calculation. Three different beam propagation methods and two direct target irradiance calculation methods are described. Kolmogorov statistics are used for turbulence simulations but you can easily use other models. This is the first electronically-published book for directed energy and makes use of web links for additional information and executable MathCAD™ code. In fact, most of the example problems used in this book have links to the Mathcad™ code so you can run the simulations yourself or modify the code for your specific applications. $9.99 for the Kindle edition and $49.99 for the hardcopy edition. Both are available on Amazon.

Table of Contents:

1 Introduction

2 The Time-Independent, Paraxial Wave Equation

2.1 The Helmholtz Equation

2.2 The Paraxial Approximation

3 The Gaussian Beam Solution

3.1 One Simple Solution for the Paraxial Wave Equation

3.2 Including Focus

3.3 Including Turbulence, Jitter and Beam Quality

4 The Huygens-Fresnel Principle

4.1 Green's Function

4.2 Fresnel Approximation

4.2.1 Including Focus

4.3 Fraunhofer Approximation

4.3.1 Single Gaussian Beams

4.3.2 Truncated Gaussian Beams

4.3.3 Single Circular Flat-top Beams

4.3.4 Single Rectangular Beams

4.3.5 Beams from Planar Waveguides

4.3.6 Beams from Arrays

5 Turbulence

6 Thermal Blooming

7 The Split-Step Fourier Transform Beam Propagation Method

7.1 Derivation

7.2 Example Simulation in Vacuum

7.3 Including Turbulence

8 The Finite-difference Beam Propagation Method

8.1 Derivation of the Two-dimensional Version

8.2 Derivation of the Three-dimensional Version

9 The Harmonic-expansion Beam Propagation Method

9.1 Derivation

9.2 Example Calculations

10 The Efficient Matrix Approach (EMA)

10.1 Derivation

10.2 Example Calculation

11 Accuracy Verification Calculation Comparisons

12 Target Irradiance Calculation Comparisons

12.1 Gaussian Beam

12.2 Circular Flat-top Beam

12.3 Rectangular Flat-top Beam

12.4 Beams from Planar Waveguides

12.5 Beams from Coherent Arrays

12.5.1 Coherent Arrays with Turbulence

13 Simulating Incoherent Tiled-array Beams

14 Beam Quality for Gaussian Beams

14.1 Optimum Truncation for Gaussian Beams

15 Beam Quality for Non-Gaussian Beams

16 Beam Quality versus Turbulence, Beam Type and Coherence

16.1 Beam Quality versus Turbulence for Various Beam Shapes

16.2 Beam Quality versus Number of Beamlets for Coherent and Incoherent Arrays

17 Laser Communications Dropouts and Turbulence

18 The Focusing Effects of Turbulence

19 High-power, Short Optical Pulses

1 Introduction

2 The Time-Independent, Paraxial Wave Equation

2.1 The Helmholtz Equation

2.2 The Paraxial Approximation

3 The Gaussian Beam Solution

3.1 One Simple Solution for the Paraxial Wave Equation

3.2 Including Focus

3.3 Including Turbulence, Jitter and Beam Quality

4 The Huygens-Fresnel Principle

4.1 Green's Function

4.2 Fresnel Approximation

4.2.1 Including Focus

4.3 Fraunhofer Approximation

4.3.1 Single Gaussian Beams

4.3.2 Truncated Gaussian Beams

4.3.3 Single Circular Flat-top Beams

4.3.4 Single Rectangular Beams

4.3.5 Beams from Planar Waveguides

4.3.6 Beams from Arrays

5 Turbulence

6 Thermal Blooming

7 The Split-Step Fourier Transform Beam Propagation Method

7.1 Derivation

7.2 Example Simulation in Vacuum

7.3 Including Turbulence

8 The Finite-difference Beam Propagation Method

8.1 Derivation of the Two-dimensional Version

8.2 Derivation of the Three-dimensional Version

9 The Harmonic-expansion Beam Propagation Method

9.1 Derivation

9.2 Example Calculations

10 The Efficient Matrix Approach (EMA)

10.1 Derivation

10.2 Example Calculation

11 Accuracy Verification Calculation Comparisons

12 Target Irradiance Calculation Comparisons

12.1 Gaussian Beam

12.2 Circular Flat-top Beam

12.3 Rectangular Flat-top Beam

12.4 Beams from Planar Waveguides

12.5 Beams from Coherent Arrays

12.5.1 Coherent Arrays with Turbulence

13 Simulating Incoherent Tiled-array Beams

14 Beam Quality for Gaussian Beams

14.1 Optimum Truncation for Gaussian Beams

15 Beam Quality for Non-Gaussian Beams

16 Beam Quality versus Turbulence, Beam Type and Coherence

16.1 Beam Quality versus Turbulence for Various Beam Shapes

16.2 Beam Quality versus Number of Beamlets for Coherent and Incoherent Arrays

17 Laser Communications Dropouts and Turbulence

18 The Focusing Effects of Turbulence

19 High-power, Short Optical Pulses

## Modeling and Simulating

Optical Waveguides

(with Solutions in Mathcad)

In this book I show you the derivation of three beam modeling and simulation techniques for optical waveguides starting from Maxwell's equation. These techniques include: split-step fast Fourier transform, finite difference, and harmonic expansion. The harmonic expansion technique is new and is the World's fastest electromagnetic beam propagation technique. I show how to use these for both scalar and full-vectoral beam propagation. This electronic book contains links in the text for accessing additional information and my source code in Mathcad™. With this book you will also receive a free copy of my new Windows software FvWoP (Full-vectoral Wave-optics Propagator). $9.99.

Table of Contents:

1 Introduction

2 Maxwell's Equations

3 Scalar, Time-independent, Paraxial Wave Equation

3.1 The Helmholtz Equation

3.2 The Paraxial Approximation

4 Fast Fourier Transform Beam Propagation Method

4.1 Derivation

4.2 Example Simulation in Vacuum

4.3 Including Refractive Index Variations to Create a Waveguide

5 Finite Difference Beam Propagation Method

5.1 Derivation of the Two-dimensional Version

5.2 Derivation of the Three-dimensional Version

5.3 Example Calculations

5.3.1 Example #1 (Multi-core Fiber)

5.3.2 Example #2 (Leaky-channel Fiber)

6 Harmonic Expansion Beam Propagation Method

6.1 Derivation

6.2 Example Calculations

6.2.1 Example # 1 (Multi-core Fiber)

6.2.2 Example #2 (Photonic-crystal Fiber)

7 Solving for Modes

7.1 General Method for Finding Waveguide Modes

7.2 The Imaginary Z-axis Propagation Mode Calculation Method

7.2.1 Finding the Fundamental Mode using HeWoP-W

7.2.2 Finding Higher-Order Modes using HeWoP-W

8 Choosing the Reference Index

8.1 Step Index with Calculated Mode Input

8.2 PCF with Estimated Mode Input

8.3 Multi-core Fibers

8.4 Leaky-channel Fibers

9 Full-vectoral and Semi-vectoral Wave Equations

9.1 Derivation

9.2 Birefringence in Waveguides

9.3 Example Simulations

9.3.1 Example #1 (Bend and Birefringence in Step-index Fiber)

9.3.2 Example #2 (Multi-core Fiber)

9.3.3 Example #3 (Leaky-channel Fiber)

9.3.4 Example #4 (Photonic Crystal Fiber)

9.3.5 Example #5 (Rib Waveguide)

9.3.6 Example #6 (9-to-1 Beam Combiner)

10 Short Optical Pulse Propagation

10.1 Example #1

Table of Contents:

1 Introduction

2 Maxwell's Equations

3 Scalar, Time-independent, Paraxial Wave Equation

3.1 The Helmholtz Equation

3.2 The Paraxial Approximation

4 Fast Fourier Transform Beam Propagation Method

4.1 Derivation

4.2 Example Simulation in Vacuum

4.3 Including Refractive Index Variations to Create a Waveguide

5 Finite Difference Beam Propagation Method

5.1 Derivation of the Two-dimensional Version

5.2 Derivation of the Three-dimensional Version

5.3 Example Calculations

5.3.1 Example #1 (Multi-core Fiber)

5.3.2 Example #2 (Leaky-channel Fiber)

6 Harmonic Expansion Beam Propagation Method

6.1 Derivation

6.2 Example Calculations

6.2.1 Example # 1 (Multi-core Fiber)

6.2.2 Example #2 (Photonic-crystal Fiber)

7 Solving for Modes

7.1 General Method for Finding Waveguide Modes

7.2 The Imaginary Z-axis Propagation Mode Calculation Method

7.2.1 Finding the Fundamental Mode using HeWoP-W

7.2.2 Finding Higher-Order Modes using HeWoP-W

8 Choosing the Reference Index

8.1 Step Index with Calculated Mode Input

8.2 PCF with Estimated Mode Input

8.3 Multi-core Fibers

8.4 Leaky-channel Fibers

9 Full-vectoral and Semi-vectoral Wave Equations

9.1 Derivation

9.2 Birefringence in Waveguides

9.3 Example Simulations

9.3.1 Example #1 (Bend and Birefringence in Step-index Fiber)

9.3.2 Example #2 (Multi-core Fiber)

9.3.3 Example #3 (Leaky-channel Fiber)

9.3.4 Example #4 (Photonic Crystal Fiber)

9.3.5 Example #5 (Rib Waveguide)

9.3.6 Example #6 (9-to-1 Beam Combiner)

10 Short Optical Pulse Propagation

10.1 Example #1

## Introduction to

High-power Fiber Lasers,

Second Edition

This hardcover book provides a comprehensive review of current high-power fiber laser (HPFL)technology. It is intended as an introduction to this rapidly developing field but can also be used by researchers and technology managers as a handy and comprehensive reference. It contains a broad review ranging from a history of HPFLs to an introduction of the science and engineering required for full HPFL systems, plus the authors’ predictions of future applications and research directions. You will also find detailed information that will help you understand and model optical waveguides, fiber amplifiers and lasers, beam combining techniques, beam quality, and free-space beam propagation. This book describes a rapidly-developing field of laser technology, and fills the very important role of providing students, researchers and technology managers with valuable, timely and unbiased information on the subject.

This second edition contains information on recent research to achieve increased output powers by increasing the power of individual beams and by combining multiple beams. It also contains new chapters on fast beam propagation modeling and simulation for optical waveguides and free space.

All proceeds from the sale of this book go to the Directed Energy Professional Society. For more information about this book follow the link below. $104.95

This second edition contains information on recent research to achieve increased output powers by increasing the power of individual beams and by combining multiple beams. It also contains new chapters on fast beam propagation modeling and simulation for optical waveguides and free space.

All proceeds from the sale of this book go to the Directed Energy Professional Society. For more information about this book follow the link below. $104.95