In this paper we demonstrate an InP-based photonic multiwavelength transmitter realized by integrating an array of DBR lasers with modulators in Mach-Zehnder configuration. An arrayed waveguide grating was used to multiplex the generated signals into a common optical output. The device was designed according to a generic integration concept, using standardized building blocks, and was fabricated in a multi-project wafer run. The device delivers up to 4 dBm of optical power into the fiber with a modulation data rate of 12.5 Gbps per transmission channel. The obtained performance makes it very promising for application in the next generation optical access networks as a key source in the central office part of the telecommunication systems.