Fu Wai Yuen, Wang Zhongqi, Cheung Yuk Fai, Choi Hoi Wai
Opt Lett. 2024 Aug 15;49(16):4505-4508. doi: 10.1364/OL.534465.
Vertical-cavity surface-emitting lasers (VCSELs) are pivotal in various applications ranging from data communication to sensing technologies. This study introduces a VCSEL design featuring a monolithic top surface high contrast grating (HCG) reflector on a thin-film substrate, aimed at improving lasing performance while reducing fabrication costs by omitting the use of distributed Bragg reflectors (DBRs). We fabricated the proposed VCSEL with the surface grating and characterized its performance through micro-photoluminescence measurements. The laser demonstrated room-temperature lasing at 436.2 nm with a Q factor of 4600 and a lasing threshold of 5.5 kW/cm under optical pumping. The implementation of the surface grating reflector was instrumental in facilitating vertical lasing, significantly improving surface reflectivity compared to conventional flat GaN/air interfaces. This innovative design holds significant promise for the development of cost-effective, DBR-free VCSELs, with potential applications extending to photonic integrated circuits and light detection and ranging (LiDAR) systems.
垂直腔面发射激光器（VCSEL）在从数据通信到传感技术等各种应用中都起着关键作用。本研究介绍了一种VCSEL设计，该设计在薄膜衬底上具有单片顶面高对比度光栅（HCG）反射器，旨在通过省略分布式布拉格反射器（DBR）的使用来提高激光性能，同时降低制造成本。我们制造了带有表面光栅的所提出的VCSEL，并通过微光致发光测量对其性能进行了表征。该激光器在436.2nm处实现了室温激光发射，品质因数为4600，光泵浦下的激光阈值为5.5kW/cm²。表面光栅反射器的实施有助于实现垂直激光发射，与传统的平面GaN/空气界面相比，显著提高了表面反射率。这种创新设计对于开发具有成本效益的无DBR的VCSEL具有重要前景，其潜在应用扩展到光子集成电路和光探测与测距（LiDAR）系统。
