The UV-induced positive and negative refractive index changes in GeO₂-SiO₂ films

¹ National Integrated Optoelectronics Laboratory, Jilin University, Changchun, 130012, P.R. China
² Department of Physics, Jilin University, Changchun, 130023, P.R. China
³ Editorial Department of Journal of Jilin University (Science Edition), Jilin University, Changchun, 130023, P.R. China

Corresponding author: zlt@jlu.edu.cn

Received: 4 February 2005
Revised: 14 May 2005
Accepted: 25 May 2005
Published online: 26 October 2005

Abstract

xGeO₂-(1-x)SiO₂ films () were deposited by flame hydrolysis deposition (FHD) on Si substrates and annealed to 1150 °C for 2 h for consolidation in air. Then the films were irradiated perpendicularly to KrF excimer laser after being hydrogen loaded to enhance the photosensitivity to UV light. X-ray photoelectron spectroscopy (XPS) was used in order to characterize the purity of the films. The film was also studied using atomic force microscopy (AFM) to determine the analytical details of the microstructure. Film thickness and refractive index were measured by variable angle spectroscopic ellipsometry (VASE). The maximum positive 0.339% and negative 0.235% refractive index changes at 1550 nm were obtained after irradiation.