This chapter explains holography through the concept of diffraction. It starts from the diffraction of a simple sinusoidal modulation also known as diffraction grating, from which are developed the notions of wave interference, efficiency, phase versus amplitude modulation, reflection versus transmission, and thick versus thin gratings. These definitions are then generalized to more complex holograms where the modulation is arbitrary. The diffraction integral equation (Kirchhoff) and its simplifications (Fresnel and Fraunhofer) are presented and used to calculate diffraction by a single slit and by multiple slits. This derivation leads to the concept of computer-generated hologram (Fourier and Fresnel). Armed with this mathematical background, the reader is then introduced to experimental holography with its different recording configurations: Gabor, Denisyuk, Leith and Upatnieks, transfer hologram, white-light hologram, holographic stereogram as well as holographic interferometry. Finally, this chapter discusses holographic recording materials such as silver halide, dichromated gelatin, photopolymer, photoresist for embossed hologram, and the much more modern electronic devices for real-time holography.
ASJC Scopus subject areas
- Physics and Astronomy(all)