Experimental Characterization of Photonic Fiber-Integrated Modulator

In this paper we present experimental characterization of a fiber-integrated, all-optical silicon based modulator. The operation principle of the proposed device is based upon plasma dispersion effect in silicon, which enables controlling the optical properties of silicon at wavelength of around 1550nm by modifying the concentration of free charges either by applying external electrical field or by using illumination in spectral range that is being absorbed by this semiconductor. The concentration of the generated free charge carriers affects the real and the imaginary part of the refractive index of the silicon semi-conductor i.e. yields controllable absorption and refraction effects over the information carrier wavelength around 1550nm. In this paper silicon slices at varied thicknesses are integrated between an input and an output fiber and the performance of the integrated all-optical modulator are characterized versus various thicknesses of the silicon layer and the wavelength of the control signal when incident on the silicon layer from both sides or from either side of it.