Optics, Global Edition

Book Preface

The creation of this 5th edition was guided by three overarching imperatives: wherever possible, to improve the pedagogy; to continue to modernize the treatment (e.g., with a bit more on photons, phasors, and Fourier); and to update the content to keep pace with technological advances (e.g., the book now discusses atomic interferometers, and metamaterials). Optics is a fast-evolving field and this edition strives to provide an up-to-date approach to the discipline, all the while focusing mainly on pedagogy. To that end there are several goals: (1) to sustain an appreciation of the central role played by atomic scattering in almost everyaspect of Optics; (2) to establish from the outset, the underlying quantum-mechanical nature of light (indeed, of all quantum particles), even as the book is grounded in traditional methodology.

Thus the reader will find electron and neutron diffraction patterns pictured alongside the customary photon images; (3) to provide an early introduction to the powerful perspective of Fourier theory, which has come to be so prevalent in modern-day analysis. Accordingly, the concepts of spatial frequency and spatial period are introduced and graphically illustrated as early as Chapter 2, right along with temporal frequency and period.

At the request of student users, I have dispersed throughout the text over one-hundred completely worked-out EXAMPLES that make use of the principles explored in each Section. More than two hundred problems, sans solutions, have been added to the ends of the chapters to increase the available selection of fresh homework questions. A complete teacher’s solutions manual is available upon request. Inasmuch as “a picture is worth a thousand words,” many new diagrams and photographs further enhance the text. The book’s pedagogical strength lies in its emphasis on actually explaining what is being discussed.

This edition furthers that approach.
Having taught Optics every year since the 4th edition was published, I became aware of places in the book where things could be further clarified for the benefit of today’s students. Accordingly, this revision addresses dozens of little sticking points, and fills in lots of missing steps in derivations. Every piece of art has been scrutinized for accuracy, and altered where appropriate to improve readability and pedagogical effectiveness. Substantial additions of new materials can be found: in Chapter 2 (Wave Motion), namely, a subsection on Twisted Light; in Chapter 3 (Electromagnetic Theory, Photons, and Light), an elementary treatment of divergence and curl, additional discussion of photons, as well as subsections on Squeezed Light, and Negative Refraction; in Chapter 4 (The Propagation of Light), a short commentary on optical density, a piece on EM boundary conditions, more on evanescent waves, subsections on Refraction of Light From a Point Source, Negative Refraction, Huygens’s Ray Construction, and The Goos-Hänchen Shift; in Chapter 5 (Geometrical Optics), lots of new art illustrating the behavior of lenses and mirrors, along with additional remarks on fiberoptics, as well as subsections on Virtual Objects, Focal-Plane Ray Tracing, and Holey/Microstructured Fibers; in Chapter 6 (More on Geometrical Optics), there is a fresh look at simple ray tracing through a thick lens; in Chapter 7 (The Superposition of Waves), one can find a new subsection on Negative Phase Velocity, a much extended treatment of Fourier analysis with lots of diagrams showing—without calculus—how the process actually works, and a discussion of the optical frequency comb (which was recognized by a 2005 Nobel Prize); in Chapter 8 (Polarization), a powerful technique is developed using phasors to analyze polarized light; there is also a new discussion of the transmittance of polarizers, and a subsection on Wavefronts and Rays in Uniaxial Crystals; Chapter 9 (Interference), begins with a brief conceptual discussion of diffraction and coherence as it relates to Young’s Experiment. There are several new subsections, among which are Near Field/Far Field, Electric Field Amplitude via Phasors, Manifestations of Diffraction, Particle Interference, Establishing The Wave Theory of Light, and Measuring Coherence Length. Chapter 10 (Diffraction), contains a new subsection called Phasors and the Electric-Field Amplitude. Dozens of newly created diagrams and photographs extensively illustrate a variety of diffraction phenomena. Chapter 11 (Fourier Optics), now has a subsection, Two-Dimensional Images, which contains a remarkable series of illustrations depicting how spatial frequency components combine to create images. Chapter 12 (Basics of Coherence Theory), contains several new introductory subsections among which are Fringes and Coherence, and Diffraction and the Vanishing Fringes. There are also a number of additional highly supportive illustrations. Chapter 13 (Modern Optics: Lasers and Other Topics), contains an enriched and updated treatment of lasers accompanied by tables and illustrations as well as several new subsections, including Optoelectronic Image Reconstruction.

This 5th edition offers a substantial amount of new material that will be of special interest to teachers of Optics. For example: in addition to plane, spherical, and cylindrical waves, we can now generate helical waves for which the surface of constant phase spirals as it advances through space (Section 2.11, p. 39). Beyond the mathematics, students often have trouble understanding what the operations of divergence and curl correspond to physically. Accordingly, the present revision contains a section exploring what those operators actually do, in fairly simple terms (Section 3.1.5, p. 51).

The phenomenon of negative refraction is an active area of contemporary research and a brief introduction to the basic physics involved can now be found in Chapter 4 (p. 114). Huygens devised a method for constructing refracted rays (p. 116), which is lovely in and of itself, but it also allows for a convenient way to appreciate refraction in anisotropic crystals (p. 358). When studying the interaction of electromagnetic waves with material media (e.g., in the derivation of the Fresnel Equations), one utilizes the boundary conditions. Since some student
readers may have little familiarity with E&M, the 5th edition contains a brief discussion of the physical origins of those conditions (Section 4.6.1, p. 122).

The book now contains a brief discussion of the Goos-Hänchen shift which occurs in total internal reflection, It’s a piece of interesting physics that is often overlooked in introductory treatments (Section 4.7.1, p. 137). Focal-plane ray tracing is a straightforward way to track rays through complicated lens systems. This simple yet powerful technique, which is new to this edition, works nicely in the classroom and is well worth a few minutes of lecture time (p. 177). Several fresh diagrams now make clear the nature of virtual images and, more subtly, virtual objects arising via lens systems (p. 176–177).

The widespread use of fiberoptics has necessitated an up-todate exposition of certain aspects of the subject (p. 208–212). Among the new material the reader can now find a discussion of microstructured fibers and, more generally, photonic crystals, both entailing significant physics (p. 212–214).

In addition to the usual somewhat formulaic, and alas, “dry” mathematical treatment of Fourier series, the book now contains a fascinating graphical analysis that conceptually shows what those several integrals are actually doing. This is great stuff for undergraduates (Section 7.3.1, p. 309–313). Phasors are utilized extensively to help students visualize the addition of harmonic waves. The technique is very useful in treating the orthogonal field components that constitute the various polarization states (p. 344). Moreover, the method provides a nice graphical means to analyze the behavior of wave plates (p. 371).

Young’s Experiment and double-beam interference in general, are central to both classical and quantum Optics. Yet the usual introduction to this material is far too simplistic in that it overlooks the limitations imposed by the phenomena of diffraction and coherence. The analysis now briefly explores those concerns early on (Section 9.1.1, p. 402).