Growth of crystalline YbVO4 thin-film optical waveguides by pulsed laser deposition

Epitaxial YbVO4 films have been grown on sapphire and Si/SiO2 substrates by pulsed laser deposition. Films were grown over a range of temperatures from 600 to 700 °C in the presence of an oxygen pressure between 2 and 20 Pa. The films were characterized by X-ray diffraction (XRD), atomic force microscopy (AFM), high-resolution scanning electron microscopy (HRSEM), and dark-mode prism coupling measurements. YbVO4 films show epitaxial growth and display one main axis orientation of (2 0 0). The degree of crystal orientation increases with increasing depositing temperature and oxygen pressure up to 700 °C and 20 Pa, respectively. AFM and HRSEM measurements show that the prepared films are dense and homogeneous and three-dimensional-island growth mechanism is confirmed. According to prism coupling measurements, sharp dip is observed for both transverse-electric (TE) and transverse-magnetic (TM) mode, which means that the light could be well confined in the prepared film.