Aerosol Deposition on Transparent Electro-Optic Films for Optical Modulators

Complex thin oxide films with electro-optic (EO) properties are promising for use in advanced optical devices because of their large EO effect. We developed a method of aerosol deposition (AD) for fabricating EO films. The mechanism for AD is based on the solidification by impact of submicron particles onto a substrate. Since particles in AD films preserve their crystalline structure during the formation of film, epitaxial growth is not necessary for exhibiting the EO effect. Highly transparent Pb(Zr, Ti)O3films, which have acceptable transmittance loss for use as optical devices, were directly deposited on glass substrates by AD. We found the Pb(Zr, Ti)O3 film by AD produced a fairly high EO coefficient (> 150 pm/V), approximately 10 times larger than that of LiNbO3. A FabryPerot (FP) optical modulator was developed with EO films fabricated by AD. We demonstrated the modulation of optical intensity with an electrical field applied to an EO film made of ferroelectric Pb (Zr, Ti)O3. key words: film deposition method, aerosol deposition, electro-optic, optical modulator