1. Department of Electrical and Electronics Engineering, Department of Physics, UNAM – Institute of Materials Science and Nanotechnology, Bilkent University, Ankara 06800, Turkey
2. Faculty of Engineering, Department of Biomedical Engineering, Osmangazi University, Eskisehir 26040, Turkey
3. LUMINOUS! Centre of Excellence for Semiconductor Lighting and Displays, Centre of Optical fiber Technology, The Photonics Institute, School of Electrical and Electronic Engineering, School of Physical and Mathematical Sciences, School of Materials Science and Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore 639798, Singapore