Optically pumped lasing at 3 μm from compositionally graded GeSn with tin up to 223% Dou, Wei ; Zhou, Yiyin ; Margetis, Joe ; Ghetmiri, Seyed Amir ; Al-Kabi, Sattar ; Du, Wei ; Liu, Jifeng ; Sun, Greg ; Soref, Richard A. ; Tolle, John ; Li, Baohua ; Mortazavi, Mansour ; Yu, Shui-Qing Abstract Publication: Optics Letters Pub Date: October 2018 DOI: 10.1364/OL.43.004558 Bibcode: 2018OptL...43.4558D