Home > Pubblicazioni > Libri Astro > Libri non fiction > Willmann-Bell > Willmann-Bell Libro Interferometry for Amateur Telescope Makers

This book has been written for the Amateur Telescope Maker — one who grinds, polishes, figures and tests optical surfaces with the objective of achieving near perfection and desires a practical guide to testing and interpreting full-aperture optical interferogram using a homebuilt interferometer.

• Chapter 1 is a nuanced exploration of the advantages and disadvantages of optical testing methods available to the amateur. Knowing the strengths and weaknesses of available testing methods is a definite benefit for deciding which method is appropriate for the particular job a hand.
• Chapter 2 explores the optical phenomena of interference and how a probe beam of light and a reference beam can be derived and interpreted from a coherent source light beam.
• Chapter 3 reviews interferometer types useful for optical testing purposes.
• Chapter 4 discusses the concept and practical methods of achieving measurement accuracy. It shows how to confirm the quality of your interferometer optics through verification with out having to resort to costly standards. Included are accuracy requirements for image capture, random errors, sampling issues, noise and sensitivity variations.
• Chapter 5 considers air turbulence, test stand effects, measuring astigmatism, retrace and design residual wavefront errors, vibration and enhancing fringe contrast.
• Chapter 6 shows how to image the fringe pattern and construction of mounts and the optical bench interferometer.
• Chapter 7 is a practical introduction to the characteristics of lasers and how they impact interferometry.
• Chapter 8 explores the waveforms produced by an optical interferometer and how they can be interpreted.
• Chapter 9 describes how to build a spherical-wave Twyman-Green form of interferometer, the Williams, that is compact, easy to set up, align, verify optically, and to understand.
• Chapter 10 shows the construction of a Bath interferometer that is very compact with a 12 or 15 mm beam splitter cube, 6 mm ball lens and a diagonal mirror and possibly a relay lens. This device is usually best for testing slower mirrors.
• Chapter 11 provides practical step-by-step guidance on how to align both the Williams and Bath interferometers. Finding the tiny returning beam can be a trying “first experience”; this chapter will show you the clever ways to track it down quickly.
• Chapter 12 deals with capturing the interference pattern produced by the interferometer. Included are such things as image scale considerations, types of cameras, exposure and issues associated which processing interferograms.
• Chapter 13 covers interferogram analysis and detailed instructions on how to use the software included with this book on a CDROM. Also included are sample images and worked examples of those images for the reader to practice on. There is no need to build your own interferometer before you actually process interferograms!
• Chapter 14 provides insights on advanced forms of interferogram analysis and a discussion of performance prediction.

The book concludes with a Glossary, six appendices and index.