1. School of Electrical & Computer Engineering, Birck Nanotechnology Center, Purdue University, 1205 West State Street, West Lafayette, Indiana 47907, USA
2. Key Lab of Optoelectronic Technology and Systems of Education Ministry of China, Chongqing University, Chongqing 400044,
China
3. Institute of Optoelectronics, Military University of Technology, 2 gen. Sylwestra Kaliskiego Street, Warsaw 00-908,
Poland