Wavelength-Tunable Laser for Signal Remodulation in WDM Access Networks Using DPSK Downlink and OOK Uplink

In this investigation, a simple wavelength-tunable laser based on a Fabry–PÉrot laser diode (FP-LD) and an erbium-doped fiber amplifier to serve as a downlink signal in a colorless wavelength-division-multiplexed passive optical network (PON) is proposed and experimentally demonstrated. The tuning range of the proposed laser is between 1529.48 and 1560.72 nm, and the output performance of proposed laser is discussed. Colorless operation is implemented by using an FP-LD and a reflective semiconductor optical amplifier in each optical network unit for uplink signal remodulation, respectively. In addition, error-free data signal remodulation using 10-Gb/s downlink differential phase-shift keying and 2.5-Gb/s uplink on–off keying is achieved in a 25-km reach PON.