Overload optical power, also known as saturated optical power, refers to the maximum input average optical power that the receiving end components can receive under a certain bit error rate of the optical module. This article provides an in-depth analysis of two key performance indicators of optical modules: transmitter power and receiver sensitivity. Modern optical modules convert electrical data to optical data to overcome losses associated with electrical transmission. With each generation, they deliver higher data rates, such as 100 Gbps, 400 Gbps, and soon 800 Gbps. It is measured in decibels (dB) or milliwatts (mW) and plays a crucial role in determining the quality and reliability of optical networks.