The electro-absorption modulated 1.55 micrometers DFB laser (EML) represents the first III-V optoelectronic integrated circuit in high volume production. The dominance of this device in dense wavelength division multiplexed telecommunications system is testimony to the advancements made in III-V fabrication technology and demonstration that OEIC's are no longer solely of academic interest. The intensed demand for higher bandwidth telecommunications systems is now pushing the EML device toward increased functionality and hence higher levels of integration. The need for wavelength selectable capability is the most prominent of these thrusts. In this talk we review the current state-of-the-art in single frequency EML technology and present design and performance results of an advanced wavelength selectable EML structure.