Spectral properties and role of aluminium-related bismuth active centre (BAC-Al) in bismuth and erbium co-doped fibres

Improving broadband emission within Bi/Er doped silicate fibres with Yb co-doping

“…A broad absorption band at λ abs ~1050 nm is also observed in both BEYDF1 and BEDF1. The measured absorption at λ abs ~1050 nm is comparable with the absorption around this region produced from BAC linked to Al (BAC-Al), as reported in BEDFs and BDFs [7,19]. in BEYDFs, emissions are measured first in BEYDF2, which is doped with lower concentrations of both Bi and Er (Table 1).…”

“…Another emission at λ em ~1100 nm combined with the Yb 3+ related emission at λ em ~1040 nm is also observed in BEYDF2. This 1100 nm emission is comparable to those emissions attributed to BAC-Al reported in Al-doped BEDFs and BDFs [7,21].…”

“…In addition, ON/OFF gain over g = + 2.4 dB/m has been observed in BEDFs, especially within λ em ~1400 nm and λ em ~1530 nm centred emission bands under λ ex = 830 nm pumping [6]. However, the emissions and gain obtained from BEDFs are not high nor uniform enough for practical use -largely due to the excited state absorption (ESA) and up-conversion (UC) processes associated with Er 3+ and BAC [4,7]. ESA and UC processes can adversely affect emissions and gain via reducing the active pump absorption [8] →BAC was reported in silica hosts and even in germanate hosts [15,16] -this provides an intriguing pathway for exploring more efficient energy transfer in more complex combinations to further expand the total emission band possible within defect rich fibres.…”

Enhanced broadband near-IR luminescence and gain spectra of bismuth/erbium co-doped fiber by 830 and 980 nm dual pumping

“…10 significant challenge is the development of broadband application for BEDF, Zinat and J. Zhang did some pioneer work in the spectral characterization of BEDF. However, only the spectral property of BEDF was specified under single 830 nm pumping, 13 in which only one or two dominant luminescence bands were observed. Y. H. Luo firstly made the efforts for 532 and 808 nm dual pumping.…”

“…According to the previous study, multiple BACs can be excited under single 830 nm pumping while 980 nm pump is proved to be quite effective for Er 3+ with a large absorption cross section ∼31.2 × 10 -22 cm 2 (Si/Al substrate). 13 Hence, 830 and 980 nm pumps are selected here to enhance and tune the bandwidth for our multicomponent BEDF. The luminescence measurement setup is depicted in Figure 2.…”