Progress made in the research and development of high-performance electrically pumped topology lasers by the Institute of Semiconductors, Chinese Academy of Sciences

Topological laser (TL) is a laser device designed and manufactured using the principles of topological optics, which can produce a robust single-mode laser and is an ideal light source for future new optoelectronic integrated chips. Electrically pumped topology lasers have become a research hotspot due to their small size and ease of integration, but topology lasers based on electrical injection are still in the early stages of research. Therefore, it is crucial to develop design ideas and technical solutions to improve the output power of electrically pumped topology lasers.

Recently, the team led by Liu Fengqi, a researcher at the Institute of Semiconductors, Chinese Academy of Sciences, has made progress in the research and development of high-performance electrically pumped topology lasers. This study innovatively introduces the design of surface metal Dirac topological cavities (SMDCs), which are prepared on the surface metal layer to preserve the integrity of the active region, providing sufficient gain for achieving high-power output, thereby solving the problem of power improvement of electrically pumped topological lasers limited by active region etching; By utilizing the strong coupling between SMDC and the active region and optimizing the design of absorption edge and topological cavity parameters under low effective refractive index difference, robust topological interband mode operation was achieved, which was validated in the robust single-mode laser spectrum and far-field mode of topological lasers with different structural parameters.

Due to the fact that the SMDC design does not damage the active region and the SMDC structure has high surface radiation efficiency, the device achieved a single mode surface emission peak power of 150 milliwatts. In addition, the device has a vortex polarization far-field, and by introducing phase modulation, while maintaining the vortex polarization characteristics of the topological laser, a symmetrical adjustable far-field is obtained. This device is an ideal on-chip vortex polarized light source.

Structure of Electric Pumped THz SMDC TL Device

This work provides new ideas for the research and development of high-performance electrically pumped topology lasers, and has positive significance for promoting the development and application of high-performance electrically pumped topology lasers. The relevant research results are titled High power electrically pumped terahertz topological laser based on a surface metal Dirac vortex activity and published in Nature Communications. The research work was supported by the National Natural Science Foundation of China, the National Key R&D Program and the Youth Innovation Promotion Association of the Chinese Academy of Sciences.

Source: Institute of Semiconductors, Chinese Academy of Sciences