Abstract: | In this letter, we report the realization of a 1.55-μm spot-size-converted (SSC) laser using conventional SCH-MQW active layers and conventional photolithography. The laser consists of a 300-μm-long rectangular gain section, with compensated multiple-quantum-well (MQW) structure, and a 300-μm-long tapered passive waveguide, fabricated on lower SCH layer. The device exhibits a beam divergence of 13°×18° and 3.5-dB coupling loss with a cleaved single-mode fiber (SMF). The 1-dB alignment tolerance is ±2.3 μm in the vertical direction and ±1.9 μm in the lateral direction, respectively |