Abstract

A study is presented on the capabilities of holographic photorefractive gratings recorded in α-phase proton-exchanged LiNbO₃ waveguides as infrared wavelength deflectors. Two different configurations have been analysed, with the grating K-vector parallel and perpendicular to the c-axis, i. e. operating under photovoltaic or diffusion dominated transport. In the parallel case, a diffraction efficiency peak η_max ∼ 20% and a bandwidth ∆λ ∼ 12 nm have been obtained for Λ = 2π /K = 6.1 µm and an effective hologram thickness L = 12 mm. In the perpendicular case, η_max ∼ 1% and ∆λ ∼ 5 nm have been obtained for Λ = 3.3 µm and L = 9 mm. The data are in excellent agreement with the behaviour expected from Kogelnik's theory.

© 2003 Optical Society of America