Optical Interferometry

FROM THE PREFACE: The aim of this book is to present a self-contained treatment of the subject with particular emphasis on recent developments and their implications for the future. A brief historical survey leads up to three chapters covering the classical concepts of two-beam interference, coherence and multiple-beam interference. Chapter 5 then discusses interference in thin films, antireflection coatings and interference filters. As mentioned at the outset, lasers are now being used to an increasing extent in optical interferometry; in fact, this has led to the virtual demise of the classical mercury arc. Accordingly, Chapter 6 looks at the laser as a light source and discusses techniques for obtaining a single-frequency output and for frequency stabilization. Five chapters then deal with applications of interferometry such as length measurement, testing optical surfaces, interference spectroscopy and Fourier-transform spectroscopy. Emphasis is placed in these chapters on techniques which have become feasible with the development of the laser, including unequal-path interferometry, fringe-counting, heterodyne and digital interferometry, fibre-optic interferometry and nonlinear interferometry. These are followed by three chapters on holography, holographic interferometry and speckle interferometry. A final chapter on stellar interferometry describes the intensity interferometer and techniques such as stellar speckle interferometry and speckle holography. Some useful mathematical results as well as some selected topics in optics are summarized for ready reference in five appendices. I have tried to plan this book so that it can be used by people who would like to apply interferometric techniques in their work as well as those who would like to learn more about interferometry. In the first instance, most topics are discussed at a level accessible to people with a basic knowledge of physical optics; a more detailed treatment for the serious worker then follows. Finally, the text is supplemented by a reference list of nearly 600 selected papers. Accordingly, students should find this book useful as a text, while researchers can use it as a reference work.