2-μm single longitudinal mode GaSb-based laterally coupled distributed feedback laser with regrowth-free shallow-etched gratings by interference lithography

Yang Cheng-Ao^{1, 2}, Zhang Yu^{1, 2}, Liao Yong-Ping^{1, 2}, Xing Jun-Liang^{1, 2}, Wei Si-Hang^{1, 2}, Zhang Li-Chun^{1, 2}, Xu Ying-Qiang^{1, 2}, Ni Hai-Qiao^{1, 2}, Niu Zhi-Chuan^{1, 2, †,}

Scanning electron micrograph of the slant ridge waveguide.