Measurements of thallium and indium doped Silicon-On-Insulator rib waveguides show optical absorption at a wavelength of 1550nm, dependent on the charge state of the associated deep-level. Therefore, it is possible to use this effect to modulate waveguide transmission by means deep-level occupancy change induce by local depletion and/or injection of free-carriers. A one-dimensional model based on the generation and recombination process described by the modified Shockley-Read-Hall (SRH) mechanism was developed using MATLAB programming language in order to compute the optical absorption of a...