Improved performance of slotted single-mode lasers

Wavelength-stabilized single mode semiconductor lasers are generally required by the dense-wavelength division-multiplexing (DWDM) communication systems. Distributed-feedback (DFB) lasers as the archetypal single mode lasers have achieved great success [1]. Such structures are conventionally fabricated with embedded grating, which requires at least one re-growth complicating the device fabrication and therefore increasing the device cost. On the other hand, single mode lasers can be easily made based on slots. Recently, by introducing a group of slots into the surface of the ridge on one side of the laser cavity, our group has successfully demonstrated that single mode lasers can be made completely dependent on a group of slots [2]. The merit of this laser platform is that it is of a single growth, can be fabricated by standard photolithography and suitable for photonic integration. In this work, we further present the slotted single mode lasers integrated with a semiconductor optical amplifier (SOA).