[OPTICAL REVIEW Vol. 13, No. 3 (2006) 161-167]
© 2006 The Optical Society of Japan

High Accuracy and High Sensitivity Measurements of the Electrooptic Effect in Undoped and MgO-Doped LiNbO3 Crystals

Kuniharu TAKIZAWA and Yuji YOKOTA

Department of Materials and Life Science, Faculty of Science and Technology, Seikei University, 3-3-1 Kichijoji-kitamachi, Musashino, Tokyo 180-8633, Japan

(Received September 2, 2005; Accepted March 20, 2006)

Accurate measurements of the composite electrooptic (EO) coefficients rc consisting of the EO coefficients r13, r33, and the piezoelectric constant d31 in undoped and MgO-doped LiNbO3 (LN) were made by extracting the fundamental and third harmonic components from photo-detection signals of the parallel Nicol optics including the LN crystal driven by minimal sinusoidal voltage. The analysis of relationship between multiple-reflection rays in the EO crystal and the accuracy of measurement indicates that anti-reflection films must be coated on the end faces of the crystal for highly accurate measurements. Measured values of rc of undoped and MgO-doped LN crystals at a wavelength of 632.8 nm were 19.8 ± 0.1 pm/V and 19.2 ± 0.1 pm/V, respectively.

Key words: electrooptic effect, electrooptic coefficient, LiNbO3, converse piezoelectric effect, piezoelectric constant