多横模垂直腔面发射激光器及其波长特性

基于氧化限制型内腔接触垂直腔面发射激光器(VCSEL) 结构设计, 研究了VCSEL的多横模分布及其模式波长分裂特性与氧化孔径尺寸、形状的关系. 在实验基础上, 通过建立有效折射率模型, 并利用标量亥姆霍兹方程的迭代算法理论, 分别对椭圆形氧化孔径和圆形氧化孔径VCSEL的横向模式特性进行模拟研究, 计算得到不同形状孔径的多横模光场分布情况, 同时测量得到高阶横模多频输出光谱. 研究发现, 椭圆氧化孔形状不仅影响横模分布特性, 还会导致每个模式的波长产生分裂, 分裂值可达0.037 nm. 同时, 随着氧化孔径的增大, 波长分裂影响会逐渐减小, 直至趋近于圆形氧化孔径的分布特性. 研究结果为进一步实现氧化限制型VCSEL的多横模锁定提供了有益参考和借鉴.

Multi-transverse-mode and wavelength split characteristics of vertical cavity surface emitting laser

We study the multi-transverse mode distributions and the wavelength splittings with different designed oxide apertures of the oxide-confined VCSEL. By developing the effective index model and BPM algorithm theory, the characteristics of transverse optical field distribution are calculated with circular aperture and ellipsoid aperture, which are compared with our experimental results of multi-wavelength spectra of high-order transverse modes. The results show that the orthogonality of the different crystal orientation modes will be broken by the oxidation-induced ellipsoid aperture, and the maximum wavelength spltting of the degenerated high-order mode is 0.037 nm, which can be reduced as the diameter of aperture increases. The results in this paper will provide a useful reference for multi-transverse mode locking of oxide-confined VCSELs.