AN EXPERIMENTAL STUDY OF THE INDIRECT PHOTOELASTIC EFFECT IN LITHIUM-NIOBATE

With a helium-neon laser operating at a wavelength of 632.8 nm, we have conducted a Brillouin spectroscopic study of the indirect photoelastic effect in lithium niobate. Scattered light was analyzed by a Fabry-Perot interferometer and signals were detected and processed by a photomultiplier and photon counting electronics.; Photoelastic matrix elements were measured in an absolute manner, using toluene as a reference scatterer. From intensity data, three of the four electrooptic tensor components were measured, and all of the symmetric photoelastic tensor components were determined.; A right angle scattering geometry was employed for all measurements. Phonons observed were (100), (001), (101), (110), (011), and (011).