We modeled and investigated the silicon microring modulator (SMM) based on a PIN junction. The proposed model’s results are in good agreement with the experimental results. The effects of various parameters were considered in an optimized model to decrease power consumption as well as increase the bandwidth and extinction ratio of the SMM. The power consumption parameter plays a key role in the modulator design. To decrease this parameter, modulator dimensions were optimized using a genetic algorithm. This was done by considering the effect of the quality factor on the gradient change of the SMM transmission profile. In comparison with experimental results, the power consumption in the presented optimized model decreased dramatically from 9.7 to 0.042 μW. In addition, the extinction ratio and bandwidth increased by 12.5% and 50%, respectively.