Design and Characterisation of Multi-Mode Interference Reflector Lasers for Integrated Photonics

InAs quantum dot ridge waveguide lasers comprising single-port multi-mode-interference-reflectors (MMIR) and single-cleaved reflectors are designed, fabricated, and characterised, to demonstrate capability for optoelectronic-integrated-circuits. Simulations of an MMIR show high values of fundamental mode reflectivity (> 80%) and good selectivity against higher order modes. Deep-etched MMIR lasers fabricated with 0.5 mm long cavities have a threshold current of 24 mA, compared to 75 mA for standard Fabry-Perot cleaved-cleaved FP-RWG lasers of the same length, both at 25 degrees C, and 56 mA compared to 102 mA at 55 degrees C. MMIR lasers exhibit stable ground state operation up to 50 degrees C and show promise as small footprint sources for integrated photonics.