Nonlinear Refractive Index Measurement of E-beam Evaporation Ta₂O₅ film

Tantalum pentoxide(Ta₂O₅) has been realized as a promising material for waveguide due to its great linear optical properties, such as high refractive index, large bandgap and so on. Recently, the nature of athermal property and high nonlinear refractive coefficient exhibit its potential for Si photonics application. In this work, using e-gun deposition growth Ta₂O₅ thin film, high quality micro-ring resonator was fabricated. The propagation loss as low as 0.3/cm was characterized from the transmission spectrum. Additionally, the nonlinear refractive coefficient (n₂) was investigated by using all optical modulation technique. The n₂ of 1.42 x 10^-14 cm²/W was estimated. Compared to the conventional materials for Si photonics, such as Si₃N₄, SiO₂ and so on, the larger n₂ value reveal the value for application.