First Demonstration of a WDM-PON System Using Full C-band Tunable SFP+ Transceiver Modules [Invited]

In this paper, a wavelength-division-multiplexing passive optical network (WDM-PON) system using small form-factor pluggable plus (SFP+) packaged full C-band tunable transceivers is demonstrated for the first time to our knowledge. Within the transceivers, a novel digital-supermode distributed Bragg reflector (DS-DBR) laser with a monolithically integrated Mach–Zehnder modulator is employed as the transmitter. A generic current control algorithm is used to drive the DS-DBR laser, which employs a laser current training sequence ensuring successful operation without the need for individual laser characterization. A pilot-tone-based feedback control loop is implemented using embedded hardware, which is able to lock the output wavelengths from three identical optical network units with less than ±3  GHz deviation from their assigned channels. Error-free transmission is achieved at a 10 GbE data rate. With the feedback control loop running continuously, the system shows a sensitivity of −23  dBm for a bit error rate of 10−12.