Tomasz Błachowicz

Application of Laser Light for Solid State Elastic Features Investigations

in a Hypersonic Range of Frequencies

Silesian University of Technology Press, Gliwice 1999, ISBN 83-88000-25-X

Table of contents

1. Introduction	9
2. Basic definitions and general description of light scattering on acoustic phonons	16
3. Review of light scattering theories in liquids and solid states	24
3.1. Motulewicz theory of light scattering in transparent crystals	24
3.2. Benedek-Fritsch theory	30
3.3. Theory of light scattering on surface phonons	40
4. Review of experimental results obtained by the Brillouin laser light scattering method	49
4.1. Gases	50
4.2. Liquids	51
4.3. Single crystals and complex crystals	54
4.4. Plastic materials	61
4.5. Glasses	64
4.6. Semiconductors	66
4.7. Metals	70
4.8. Thin layers and multi-layered structures	71
4.9. Superlattices .	77
5. The Fabry-Perot interferometer in Brillouin laser light scattering experiments	80
5.1. Introduction	80
5.2. A single interferometer in a multi-pass configuration	81
5.3. A tandem interferometer in a multi-pass configuration	86
6. The Single photon counting method in Brillouin laser light scattering experiments	94
6.1. Introduction	94
6.2. Detailed description of the experimental equipment for single photon counting method	95
6.3. Filtration of detected signals	104
7. Experimental equipment in the Brillouin laser light scattering measurements	108
7.1. Introduction	108
7.2. Experimental setup	111
8. Theory of Brillouin scattering in the piezoelectric crystals	123
8.1. Influence of the piezoelectric effect on the velocity and frequency of the hypersonic acoustic wave	123
8.2. Determination of scattering configurations on selected crystallographic planes	134
9. Examples of calculations of velocities, frequencies and states of polarization     of acoustic waves for selected crystallographic directions	145
9.1. Detailed calculations for a scattering configuration not leading to the determination of elastic constants of the LiTaO3 crystal	145
9.2. Detailed calculations for a scattering configuration useful for the c11 elastic constant determination in the LiTaO3 crystal	151
9.3. Detailed calculations for a scattering configuration useful for the c44 and the c33 elastic constants determination in the LiTaO3 crystal	156
9.4. Detailed calculations for a scattering configuration useful for the c13 and the c14 elastic constants determination in the LiTaO3 crystal	160
9.5. Detailed calculations for a scattering configuration useful for the c66 and the c12 elastic constants determination in the LiTaO3 crystal	165
10. Results of Brillouin laser light scattering in the LiTaO3 crystal	171
10.1. Physical properties of the LiTaO3 crystal	171
10.2. Results of measurements of elastic constants, velocities and frequencies of hypersonic acoustic waves in the LiTaO3 crystal	172
10.3. Discussion of experimental results	183
11. Summary of results	188
References	193
Basic symbols	213
Index	217
Summary	223