1. Department of Polymer Chemistry and Technology Kaunas University of Technology Radvilenu pl. 19 Kaunas LT‐50254 Lithuania
2. Graduate Institute of Photonics and Optoelectronics National Taiwan University 1, Section 4, Roosevelt Road Taipei 10617 Taiwan
3. Department of Electrical Engineering Yuan Ze University 135 Yuan‐Tung Road Taoyuan 32003 Taiwan