I started writing the Engineering column of Optics & Photonics News (OPN) in early 1997. Since then nearly forty articles have appeared, covering a broad range of topics in classical optical physics and engineering. My original goal was to introduce students and practising engineers to some of the most fascinating topics in classical optics. This I planned to achieve with minimal usage of the mathematical language that pervades the literature of the field. I had met many bright students and practitioners who either did not know or did not fully appreciate some of the major concepts of classical optics such as the Talbot effect, Abbe's sine condition, the Goos–Hänchen effect, Hamilton's internal and external conical refraction, Zernike's method of phase contrast, Michelson's stellar interferometer, and so on. My columns were going to have little mathematics but an abundance of pictures and pedagogical arguments, to bring forth the essence of the physics involved in each phenomenon. In the process, I hoped, the readers would appreciate the beauty of the subject and, if they found it interesting, would dig deeper by searching the cited literature.
A unique tool available to me for this purpose was the computer programs DIFFRACTTM, MULTILAYERTM, and TEMPROFILETM, which I have developed in the course of my research over the past 20 years. The first of these programs simulates the propagation of light through optical systems consisting of discrete elements such as lasers, lenses, mirrors, prisms, phase/amplitude masks, gratings, polarizers, wave-plates, multilayer stacks, birefringent crystals, diffraction gratings, and optically active materials.