Output light power of InGaN-based violet laser diodes improved by using a u-InGaN/GaN/AlGaN multiple upper waveguide - 梁锋;赵德刚;江德生;刘宗顺;朱建军;陈平;杨静;刘炜;刘双韬;邢瑶;张立群;王文杰;李沫;张源涛;杜国同 (Chinese physics B, 2017)