What is a hologram?

Abstract

This work introduces a non-expert to holography by way of answering a simple question, "What is a hologram?" The discussion focuses on optical holograms developed in silver halide films and utilizing the visible region of spectrum. This work is divided into two major parts: lecture and demonstration. The lecture part deals with basic concepts in holography. With minimal mathematics, basic principles in holography are first presented. Its similarities and differences with ordinary photographic process are explained. Different holographic applications, such as displays, surface profiling, interferometry, are discussed. The demonstration part shows an actual step-by-step process of developing holograms using films. The author attempts to use holography as a teaching tool in a regular optics class.