Overload point is the overload optical power. It indicates. SMSR is the ratio of the average optical power of the main mode to the optical power of the most significant side mode under the worst transmission conditions. The transmitted optical power is related to the proportion of "1"s in the transmitted data signal; the more "1"s, the. The maximum receivable power is called the Overload Optical Power, also called the Saturation Power, which means max optical power detected by the receiving end of the optical module.