Design and Performance Study of 1.65 μm AlGaInAs/InP Symmetric Multi-Quantum Well Semiconductor Laser Epitaxial Structure

Semiconductor lasers operating at 1.65 μm are critically important for applications in laser remote sensing, free-space optical communication, and LiDAR systems, owing to their eye-safe wavelength (1.45–1.70 μm), excellent atmospheric transmission, and compatibility with high-sensitivity photodetectors. Conventional 1.65 μm solid-state and fiber lasers face challenges in terms of system complexity and physical size. To address this, we propose a compact and high-performance solution via the design and fabrication of a symmetric multi-quantum well (MQW) semiconductor laser epitaxial structure based on the AlGaInAs/InP material system. Through systematic bandgap engineering, we designed an active region comprising In0.86Ga0.05Al0.09As/In0.78Ga0.10Al0.12As quantum wells to achieve the target 1.65 μm emission. Detailed theoretical analysis reveals that an indium composition of 0.86 and a quantum well thickness of 6 nm yield optimal optical gain characteristics at this wavelength. The epitaxial structure was grown by the metal-organic chemical vapor deposition (MOCVD), with X-ray diffraction (XRD) and photoluminescence (PL) spectra confirming successful 1650 nm light emission. Finally, the P-I-V curve was obtained at 25°C and the maximum output power was 19.5 mW. This work establishes a new paradigm for developing miniaturized, high-efficiency 1.65 μm semiconductor lasers, offering significant potential for next-generation LiDAR and space communication technologies.