Receiver sensitivity is a critical parameter in optical communication systems, determining the minimum optical power required to achieve a specified bit error rate (BER) or signal-to-noise ratio (SNR). In essence, it measures how well a receiver can detect weak optical signals. What Is BER? The bit error rate (BER) measures the data transmission precision within. 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). Receiver sensitivity is defined by how.