The electro-optic coefficients of GaAs: Measurements at 1.32 and 1.52 μm and study of their dispersion between 0.9 and 10 μm

Abstract

The linear (r41) and quadratic (R11 and R12) electro-optic coefficients of GaAs have been measured at the wavelengths 1.32 and 1.52 μm using single-mode AlGaAs/GaAs strip-loaded waveguides. The results are r41=−(1.54±0.08)×10−10 cm/V, R11=−(9.3±2.8)×10−17 cm2/V2 and R12=−(5.1±l.9)×10−17 cm2/V2 at 1.32 μm and r41=−(1.50±0.08)×10−10 cm/V, R11=−(3.2±2.3)×10−17 cm2/V2 and R12=−(5.1±2.6)×10−17 cm2/V2 at 1.52 μm. These results, together with those previously measured at different wavelengths, are compared with published theoretical models. The linear electro-optic coefficient r41 is slightly dispersive near the band gap and roughly constant for longer wavelengths, in good agreement with the models. The quadratic electro-optic coefficients drop rapidly with increasing wavelength, in good agreement with a model based on electroabsorption.