Strong blue emission from Pr3+ ions through energy transfer process from Nd3+ to Pr3+ via Yb3+ in tellurite glass.

Energy transfer excited upconversion emission in Nd3+/Pr3+-codped tellurite glass have been studied on pumping with 800nm wavelength. The upconversion emission bands from Pr3+ ion are observed at the 488, 524, 546, 612, 647, 672, 708 and 723nm due to the (3P0+3P1)→3H4, 3P1→3H5, 3P0→3H5, 3P0→3H6, 3P0→3F2, 3P1→3F3, 3P0→3F3 and 3P0→3F4 transitions, respectively. The addition of ytterbium ions (Yb3+) on the upconversion emission intensity is also studied and result shows an eight times enhancement in the upconversion intensity at 488nm from Pr3+ ions. The pump power and concentration dependence studies are also made. It is found that Yb3+ ions transfer its excitation energy to Nd3+ from which it goes to Pr3+. No direct transfer to Pr3+ is seen. This is verified by codoping Nd3+ and Pr3+ into the host.