This paper presents the results of measurements by the Sénarmont compensator method of the dc electrooptic coefficients at a wavelength of 6328 Å and observations of electro-optic modulation at radio frequencies in single-domain crystals of lithium niobate (LiNbO<sub>3</sub>), a trigonal crystal of point group 3<i>m</i>. Tables of electro-optic properties and measurements are included, as well as a series of optical interference figures for various static field conditions. The magnitudes of the dc coefficients were found to be <i>r</i><sub>22</sub> = 2.0×10<sup>-7</sup> cm/statvolt and |0.9<i>r</i><sub>33</sub>-<i>r</i><sub>13</sub>|= 5.2×10<sup>-7</sup> cm/statvolt.
P. V. LENZO, E. G. SPENCER, and K. NASSAU, "Electro-Optic Coefficients in Single-Domain Ferroelectric Lithium Niobate," J. Opt. Soc. Am. 56, 633-635 (1966)