Dependence of optically preamplified receiver sensitivity on optical and electrical filter bandwidths-measurement and simulation

In this letter, we investigate both experimentally and by means of simulations, the dependence of receiver sensitivity on the optical filter bandwidth as well as on the bandwidth of the detection electronics for the optical noise limited direct detection case. The experiment is in good agreement with simulations employing advanced Gaussian noise statistics. Bandwidth optimization is performed both for nonreturn-to-zero and return-to-zero coded signals, yielding a measured sensitivity only 1.4 dB off the quantum limit at a data rate of 10 Gb/s.