Gao, Xingwei
Hsu, Chia Wei
Zhen, Bo
Lin, Xiao
Joannopoulos, John D.
Soljačić, Marin
Chen, Hongsheng
Article History
Received: 13 April 2016
Accepted: 25 July 2016
First Online: 25 August 2016
Competing interests
: The authors declare no competing financial interests.