Explicit expressions for the receiver sensitivity and system penalties of optically preamplified direct-detection systems

Novel analytical closed-form expressions for the receiver sensitivity of an optically preamplified direct-detection transmission system and the system power penalties arising from excess electrical and optical filter bandwidths and finite extinction ratio are presented. An explicit analytical expression covering the combined effects of APD noise, receiver circuit noise, finite extinction ratio, electrical and optical filter bandwidths, amplifier noise, and input coupling loss is given. These results form a useful basis for the design of high sensitivity optically preamplified transmission systems.<<ETX>>