Electroabsorption-modulated widely tunable DBR laser transmitter for WDM-PONs

We present an InP-based distributed Bragg reflector (DBR) laser transmitter which has a wide wavelength tuning range and a high chip output power for wavelength division multiplexing passive optical network (WDM-PON) applications. By butt-jointing InGaAsP with 1.45μm emission wavelength as the material of the grating section, the laser wavelength can be tuned for over 13nm by the DBR current. Accompanied by varying the chip temperature, the tuning range can be further enlarged to 16 nm. With the help of the integrated semiconductor optical amplifier (SOA), the largest chip output power is over 30mW. The electroabsorption modulator (EAM) is integrated into the device by the selective-area growth (SAG) technique. The 3dB small signal modulation bandwidth of the EAM is over 13 GHz. The device has both a simple tuning scheme and a simple fabrication procedure, making it suitable for low cost massive production which is desirable for WDM-PON uses.