Raman and Brillouin Scattering J R Leonard Talk

Raman and Brillouin Scattering J. R. Leonard

Talk Outline • Basic Idea • Distinction Between Raman and Brillouin Scattering • Instrumentation • Brillouin Theory and Example • Raman Theory and Examples

Basic Idea • Light scatters of a solid emitting or absorbing a phonon. • Follows conservation of energy and momentum. Ashcroft and Mermin

Sample Spectrum H. Z. Cummins and P. E. Schoen, in Laser Handbook, edited by F. T. Arecchi and E. O. Schultz-Dubois (North Holland, Amsterdam, 1972), p. 1029

Distinction • Two types of phonons, optical and acoustic. • Raman scattering measures optical phonons. • Brillouin scattering measures acoustic phonons. Kittel

Raman Instrumentation H. Z. Cummins and P. E. Schoen, in Laser Handbook, edited by F. T. Arecchi and E. O. Schultz-Dubois (North Holland, Amsterdam, 1972), p. 1029

Brillouin Instrumentation H. Z. Cummins and P. E. Schoen, in Laser Handbook, edited by F. T. Arecchi and E. O. Schultz-Dubois (North Holland, Amsterdam, 1972), p. 1029

Classical Look at Brillouin Scattering • Long wavelength limit allows lattice to be treated as a continuum. • Scattering is off moving lattice distortions (phonons). • Follows Braggs Law in the phonon’s reference frame. Ashcroft and Mermin

Some Equations Ashcroft and Mermin, M. H. Grimsditch and A. K. Ramdas, Phys. Rev. B 11 (1975), 3139

Where the Tensor came from H. Z. Cummins and P. E. Schoen, in Laser Handbook, edited by F. T. Arecchi and E. O. Schulz-Dubois (North-Holland, Amsterdam, 1972), p. 1029.

Data Analysis - Diamond

Data Analysis - Diamond • Used the model to calculate elastic moduli of diamond. • Intensity of lines consistent with other’s calculation of elasto-optic constants. M. H. Grimsditch and A. K. Ramdas, Phys. Rev. B, 11 (1975) 3139.

Raman Spectra John R. Ferraro and Kazuo Nakamoto, Introductory Raman Spectroscopy, Academic Press, Boston (1994), p. 15 -16.

Diamond Thin Films Robert E. Shroder, Diamond and Diamond-Like Thin Films: A Raman Scattering Analysis of Carbon Bonding North Carolina State University Master’s Thesis, 1988.