Piezoelectric transparent thin films are of great interest for use in tunable filters. We present experimental results on Ta<sub>2</sub>O<sub>5</sub> single layers coated on fused-silica substrates with an electron-beam deposition process. Above 450 °C, coatings change from an amorphous to a polycrystallized structure. When this structure shows a preferred orientation matching the piezoelectric tensor of the Ta<sub>2</sub>O<sub>5</sub> crystal and the external electric field, variation in the piezoelectric layer thickness is expected. We detail experimental results in terms of optical (spectrophotometric and scattering measurements) and nonoptical characterizations (x-ray diffraction and scanning electron microscopy). Then the resultant thickness variation under oscillating applied voltage is measured with an extrinsic Fabry-Perot interferometer setup.
© 2002 Optical Society of America
Rémy Parmentier, Fabien Lemarchand, Michel Cathelinaud, Michel Lequime, Claude Amra, Stéphane Labat, Stéphanie Bozzo, Franck Bocquet, Ahmed Charaï, Olivier Thomas, and Christian Dominici, "Piezoelectric Tantalum Pentoxide Studied for Optical Tunable Applications," Appl. Opt. 41, 3270-3276 (2002)