Ion-implanted planar waveguides in barium sodium niobate

Planar optical waveguides have been formed in Y-cut barium sodium niobate by He+ ion implantation.Refractive index profiles have been determined for n0 and ne using our dark-mode-spacing reflectivity calculation at 0.633 and 0.488 μm. The profiles are similar to those reported for LiNbO3 with optical barriers having −Δn∼5.5% for n0 and ∼3.5% for ne (at a dose of 3×1016 cm−2), and with an anomalous index increase in the guiding region for ne. The sharp modes suggest losses of a few dB/cm, and guide stability up to 500 °C has been determined.