Measurement of nonlinear optical properties of silicon waveguide at 1.55 /spl mu/m wavelength

Summary form only given. Silicon integrated optical waveguides of several centimetres in length can now be routinely made with linear losses below 0.4 dB/cm and effective areas which are over a magnitude smaller than standard single mode optical fiber. At a wavelength of 1.55 /spl mu/m, two-photon absorption should be insignificant in silicon because the photon energy is less than half the direct bandgap of silicon. Silicon waveguides are thus attractive candidates for ultrafast all-optical switching applications at the wavelengths of interest for optical communications. However to date there has been no experimental study of the nonlinear refractive index n/sub 2/ of silicon at 1.55 /spl mu/m, although there has been a prior study at a wavelength of 10.6 /spl mu/m. We report an experimental measurement of n/sub 2/ for a silicon waveguide at 1.55 /spl mu/m and also estimate an upper bound on the value of the two-photon absorption coefficient. Knowledge of these parameters is essential if one is to proceed in the design of an ultrafast all-optical switch using silicon waveguides.