Noise and intersymbol-interference properties of OTDM and ETDM receivers

We experimentally and theoretically confirm the similar performance of optical time-division demultiplexing (OTDM) and electrical time-division demultiplexing (ETDM) receivers for beat-noise limited return-to-zero signal detection. OTDM receivers show a slight sensitivity advantage, largely independent of parameters like the receiver´s optical filter bandwidth or center frequency. The OTDM sensitivity benefit is caused by reduced intersymbol-interference properties of the OTDM receiver, as well as by the suppression of beat noise by the temporal demultiplexing window. The latter effect can be captured by extended expressions for the beat-noise variances presented in this letter.