Design and optimization of DBR in 980 nm bottom-emitting VCSEL. - Te Li; Yongqiang Ning; ErJuan Hao; JinJiang Cui; Yan Zhang; GuangYu Liu; Li Qin; Yun Liu; Lijun Wang; DaFu Cui; ZuYan Xu (Sci. China Ser. F Inf. Sci., 2009)