1. Institute of Physics Academia Sinica Taipei 11529 Taiwan
2. Department of Electrical and Photonics Engineering Technical University of Denmark 2800 Lyngby Denmark
3. Department of Physics National Taiwan University Taipei 10617 Taiwan
4. University of Chemistry and Technology Prague Department of Inorganic Chemistry Technická 5 Prague 6 16628 Czech Republic
5. Graduate Institute of Applied Physics National Taiwan University Taipei 10617 Taiwan
6. Aston Institute of Photonic Technologies Aston University Birmingham B4 7ET UK
7. Center for Condensed Matter Sciences National Taiwan University Taipei 10617 Taiwan
8. Department of Mechanical Engineering Chung Yuan Christian University Taoyuan 32023 Taiwan
9. Research Center for Semiconductor Materials and Advanced Optics Chung Yuan Christian University Taoyuan 32023 Taiwan