GaN基垂直腔面发射激光器的研制

Fabrication of GaN-based Vertical Cavity Surface Emitting Lasers

作者在我国大陆首次实现了GaN基垂直腔面发射激光器(VCSEL)的激射.首先采用金属有机物化学气相沉积(MOCVD)技术在蓝宝石衬底上进行高质量氮化物增益区的外延生长,然后在表面沉积高反射介质膜分布布拉格反射镜(DBR).将样品键合到其它支撑片上后,采用激光剥离技术将蓝宝石衬底去除.再在去除蓝宝石后露出的氮化物表面沉积第二组介质膜DBR制成VCSEL.在室温光泵条件下,观察到VCSEL的激射,激射波长449.5 nm,阈值6.5 mJ/cm2,激射峰的半高宽小于0.1 nm,这些指标达到了国际领先水平.本文为进一步研制实用化氮化物VCSEL奠定了重要的基础.

OaN-based vertical surface emitting lasers （VCSELs） have potential applications in various fields such as high-density optical storage. This paper is the first report in mainland of Chins on lasing action of GaN-based VCSEL. High-quality nitride active gain region was grown on an Al2O3 sapphire substrate using metalorganic chemical vapor deposition （MOCVD）. Then a high-reflectivity dielectric distributed Bragg reflector （DBR） was deposited on the surface. After bonding a supporting plate on the surface, the sapphire substrate was removed by a laser-lift-off method and the second dielectric DBR was deposited on the exposed GaN surface to form a VCSEL structure. Lasing action was confirmed under optical pumping at room temperature. The lasing wavelength,threshold and linewidth were 449.5 nm, 6.5 mJ/cm^2 and 0.1 nm, respectively. The threshold and linewidth are better than those ever reported. The result of this work laid important foundation of current-injected VCSEL based on nitride semiconductors.