Silicon-based optoelectronic chips have a wide range of applications in the fields of artificial intelligence, ultra-large-scale data centers, high-performance computing, light radar (LIDAR) and microwave photonics. Monolithically integrated silicon-based lasers have the advantages of low power consumption and high integration, and are the development trend of optical interconnection and high-speed optical communication chips in the future. In recent years, significant progress has been made in the direct epitaxial growth of III-V quantum dot (QD) lasers on silicon substrates, laying a solid foundation for silicon-based optoelectronic integration, but the single-body integration of silicon-based lasers and optoelectronic devices has not yet been realized. chip integration.
Institute of Physics, Chinese Academy of Sciences/Beijing National Research Center for Condensed Matter Physics Zhang Jianjun, Wang Ting, and Wang Zihao have been focusing on silicon-based light sources for large-scale silicon-based optoelectronic integration in recent years, and have made important progress in the direction of silicon-based integrated lasers. It is in the forefront of related research fields internationally.
Representative works in recent years include realizing the widest flat-top quantum dot frequency comb laser, and four laser arrays can reach a transmission rate of 4.8Tbit/s (Photon. Res. 2022; 10, 1308); The injection locking method realized silicon-based epitaxial III-V narrow-linewidth quantum dot lasers (Photon. Res. 2022; 10, 1840); the first SOI-based monolithically integrated InAs quantum dot single transverse mode laser (ACS Photon. 2023; 10, 1813). The team has recently cooperated with Su Yikai, Guo Xuhan of Shanghai Jiaotong University, and Wei Wenqi of Songshan Lake Materials Laboratory. The point laser and the silicon waveguide are integrated on the same SOI substrate, and the light of the silicon-based laser is successfully coupled to the silicon waveguide through the end face, realizing the monolithic integration of the laser and the waveguide for the first time. Excellent research work with impact, this is a major advance in the field of integrated photonics."
The researchers studied the L-I curves of embedded lasers at different temperatures and the output power after coupling. In the continuous wave (CW) current operation mode, the laser lasing temperature can reach above 95°C, and the threshold current at room temperature is about 50mA. When the injection current is 250mA, the maximum output power is 37mW. At an injected current of 210mA, the embedded laser coupled out an optical power of 6.8mW through a silicon waveguide (Fig. 2). In addition, it was found that edge couplers with multiple tapered tips have higher coupling efficiency due to their spot size more similar to the mode profile of the laser compared to common reverse tapered couplers with a single tip and better alignment tolerances.
