Burst-mode optical transmitter with DC-coupled burst-enable signal for 2.5-Gb/s GPON system

In this paper, first burst-mode transmitter for 2.5-Gb/s gigabit-capable passive optical networks (GPON) system is evaluated. Small form factor (SFF) type optical network unit (ONU) generates 2.5-Gb/s optical eyes with commercial distributed feedback-laser diode (DFB-LD). For the fast burst signal access, burst enable (BEN) connection on the evaluation board utilizes DC-coupling configuration. Resultant optical output waveform shows 16.30 dB extinction ratio with wide eye opening for GPON mask test. No significant eye degradation is detected in high temperature operation and after 10 km distance transmission. Proposed GPON ONU successfully shows fast timing characteristics of 2.17 nsec for Tx enable stage and 1.17 ns for Tx disable stage.