基于晶格匹配纳米多孔GaN分布布拉格反射镜结构的电泵浦蓝光VCSEL研究

蓝光垂直腔面发射激光器（VCSEL）在高密度光存储、激光显示、激光照明、水下通信、海洋资源探测及激光生物医学等领域具有广阔的应用前景。如何获得高质量氮化物异质结分布布拉格反射镜（DBR）成为制作GaN基VCSEL的一个主要难点。目前通过电化学蚀刻制备氮化镓/纳米多孔氮化镓（GaN/NP-GaN）DBR结构是获得高质量晶格匹配纳米多孔GaN DBR的一种新方法，该结构具有折射率差值较大的优势，有利于获得高反射率和较宽的高反射带宽。尽管这种纳米多孔DBR结构VCSEL具有导电性能，但仍存在较高的串联电阻和注入电流侧向泄露两个难题，导致其阈值电流密度升高。因此，本项目基于晶格匹配纳米多孔GaN DBR结构，研究不同类型的电流注入孔径VCSEL结构设计及其制作工艺，为解决VCSEL串联电阻高、注入电流侧向泄露、电流注入孔径的制备等问题提出新思路，进而实现电泵浦蓝光VCSEL室温激射。

Vertical Cavity Surface Emitting Lasers (VCSELs) emitting in the blue wavelength has promising application prospects in high-density optical storage, laser display, laser lighting, underwater communication, ocean resource exploration and laser biomedical fields. .One of the main difficulties is the fabrication of high-quality epitaxial Distributed Bragg Reflectors (DBRs) for current injected GaN-based VCSEL. Now a new approach that yields lattice-matched epitaxial DBRs is to obtain nano-porous which can be achieved by the controlled electrochemical etching of highly doped n-type GaN. The DBR has the advantage of high-index-contrast, which is helpful to obtain high reflectivity and wide reflectivity bandwidth. .However, although the nano-porous GaN DBRs with high reflectivity offer electrical conductivity, there are still two problems to be overcome: the high series resistance and side leakage of current injection resulting in higher threshold current density of VCSEL..Therefore, this project proposes a new method to achieve the current-injected GaN-based VCSELs emitting lasers based on lattice-matched nano-porous GaN DBRs at room temperature, by studying the design and fabrication of VCSELs with various types of current-injected apertures to reduce the lateral leakage of injecting current while maintaining lower series resistance.