Monolithic integration of single facet slotted laser, SOA, and MMI coupler

We demonstrate a monolithically photonic integrated circuit (PIC) comprising a single facet slotted laser (SFSL), a semiconductor optical amplifier (SOA), and a 1 × 2 multimode interference (MMI) coupler. The integrated SFSL generates a tunable single longitudinal mode output, and utilizes a simplified fabrication process for the PIC when compared with distributed feedback or distributed Bragg reflector lasers by eliminating the epitaxial regrowth as well as the ebeam or holographically generated gratings. The integration technique is implemented by biasing the MMIs to transparency, which makes the fabrication comparable the standard ridge waveguide laser. The demonstrated PIC can be used as a 1 × 2 splitter or by integrating with other waveguide devices, such as laser, modulators, or SOAs, to realize different functionality.