[1] Natl Cheng Kung Univ, Dept Photon, Tainan 70101, Taiwan
[2] Natl Cheng Kung Univ, Adv Optoelect Technol Ctr, Tainan 70101, Taiwan
[3] Natl Chung Hsing Univ, Grad Inst Precis Engn, Taichung 40227, Taiwan
[4] Peking Univ, State Key Lab Nucl Phys & Technol, Beijing 100871, Peoples R China
[5] Natl Cheng Kung Univ, Dept Mat Sci & Engn, Tainan 70101, Taiwan
[6] Natl Sun Yat Sen Univ, Dept Phys, Kaohsiung 80424, Taiwan
[7] Natl Sun Yat Sen Univ, Ctr Nanosci & Nanotechnol, Kaohsiung 80424, Taiwan