In an optical transmission system, one essential parameter in determining the system power budget is the optical receiver sensitivity, which is defined as the minimum average optical power for a given bit error rate (BER). To make a good optical receiver design, it is critical to understand the different parameters that will cause impairments in the overall receiver sensitivity. This application note provides an in-depth analysis of the complete receiver optical sensitivity and the potential power penalties related to the accumulation of random noise and inter-symbol interference (ISI) in both amplitude and timing. The analysis is based on normal receiver sensitivity assuming an ideal input signal with negligible impairment such as ISI, rise/fall time, jitter, and transmitter relative intensity noise (RIN). Read full article.