Author Affiliations

Qian Li,¹ K Nakkeeran,² and P. K. A. Wai^1,*

¹Photonics Research Center, Department of Electronic and Information Engineering, The Hong Kong Polytechnic University, Hong Kong

²School of Engineering, Fraser Noble Building, King’s College, University of Aberdeen, Aberdeen, AB24 3UE, U.K.

^*Corresponding author: enwai@polyu.edu.hk