What determines the maximum permissible end to end system attenuation in a given fiber link?

The maximum permissible end-to-end system attenuation in a given fiber link is fundamentally determined by the average transmitter power and the receiver sensitivity. This relationship is crucial because it sets the limits for how much signal can be lost as it travels through the fiber, ensuring that the signal remains within acceptable parameters for the receiver to interpret correctly.

Transmitter power refers to the strength of the optical signal generated by the source, while receiver sensitivity indicates the minimum optical signal level that the receiver can detect and accurately process. If the total attenuation—encompassing fiber loss, connector losses, splice losses, etc.—exceeds the difference between the transmitter power and the receiver sensitivity, the system will not function reliably. This balance is vital to ensure adequate signal integrity from end to end.

Other factors, such as cable attenuation, environmental conditions, and connector quality, do play roles in overall system performance and reliability, yet they do not directly establish the maximum permissible attenuation limit. Instead, it is the link between the power output of the transmitter and the input requirements of the receiver that fundamentally defines this critical parameter.