The Scattering of Laser Light by Ruby Crystals

The use of a laser as a light source for studying light scattering from solids is discussed and results are presented of an investigation of the scattering of laser light by ruby crystals. Both single particle and bulk scattering were studied as a function of crystal growth direction, annealing, boule morphology, polarization, chromium concentration, γ irradiation, and temperature. Randomly distributed scatterers, decorated small-angle grain boundaries, and gross scattering regions were all observed by laser ultramicroscopy. The intensity of the scattered light was monitored vs scattering angle and crystal orientation. It appears from the results of these bulk-scattering measurements that the scattering can be attributed to regions in the crystals which lie in specific planes and are oriented in specific directions. There is some indication that the individual scattering units may consist of impurity precipitates.