Developing Si compatible optical sources has attracted a great deal of attention owing to the potential for forming inexpensive, monolithic Si-based integrated devices. In this Letter, we show that ultra broadband near-IR (NIR) luminescence in the optical telecommunication window of silica optical fibers was obtained for Bi-doped silicon- rich silica films prepared by a co-sputtering method. Without excess Si, i.e., Bi-doped pure silica films, no luminescence was observed in the NIR range. A broad Bi-related NIR photoluminescence appears when excess Si was doped in the Bi-doped silica. The luminescence properties depended strongly on the amount of excess Si and the annealing temperature. Photoluminescence results suggest that excess Si acts as an agent to activate Bi NIR luminescence centers and also as an energy donor to transfer excitation energy to the centers. It is believed that this peculiar structure might find some important applications in Si photonics.
© 2011 Optical Society of America
Original Manuscript: September 6, 2011
Manuscript Accepted: September 20, 2011
Published: October 26, 2011
Yuji Miwa, Hong-Tao Sun, Kenji Imakita, Minoru Fujii, Yu Teng, Jianrong Qiu, Yoshio Sakka, and Shinji Hayashi, "Sensitized broadband near-infrared luminescence from bismuth-doped silicon-rich silica films," Opt. Lett. 36, 4221-4223 (2011)