ABSTRACT
The basic idea for holography was proposed in 1947 by Gabor. K. S. Pennington added that with holography it is possible to do interferometry with almost any type of material. Holographic interferometry may also include continuous exposure as well as multiple exposures. When it becomes practical to transmit holograms at a distance, this continuous exposure interferometry will be able to monitor continuously pictures of materials under stress. Briefly, accoustical holography is a combination of acoustics and holography. The ruby laser, normal mode and Q-switched, He-Ne, and the argon are lasers commonly used at the present to produce the hologram. Holograms may be made on film, glass, metal, or even ceramics. There is much value in picture holograms independent of interferometry and computer generated holograms. Laser acoustical optical technology has been used in experimental spectrum analyzers with the use of the Zenith-D-70R Acoustical Optical Deflector and also used as an actual hard copy printer.
