Upconversion luminescence characteristics of Er / Yb / P codoped double cladding fiber based on nanoporous silica glass

The double cladding Er/Yb/P co-doped fiber was fabricated by rod-in-tube method, in which the doped nanoporous silica glass (NPSG) was used as the core, the high-purity silica was used as the inner cladding. Under 980 nm laser excitation, the fiber has strong up-conversion luminescence, and its spectrum has luminescence peaks at 518 nm, 543 nm and 650 nm. The integrated intensity of the peak area at 518 nm, 543 nm and 650 nm has a strong linear relationship with the pump power in the double logarithmic coordinate system. By adjusting the fiber length and pump power, the relative luminescence intensity of 518 nm, 543 nm and 650 nm was changed, and different shapes of spectra were obtained. The mechanism of up-conversion luminescence tailoring with the fiber length and pump power has been investigated.