Near Infrared And Upconversion Luminescence Of Er～(3+),Tm～(3+) And Yb～(3+) In New Glasses

In this paper, the near infrared luminescence and upconversion luminescence properties of rare earth doped cadmium aluminium silicate (CAS), calcium aluminium silicate(CaAS) and calcium aluminium germanate (CaAG) glasses have been studied. The main contents and the important results of this paper are as following: Intense emissions at 1534 ntn were observed in Er3+-doped above mentioned new glasses under the excitation of a 488 rim Ar laser. However, the emissions in the visible range were weak. These results were mainly attributed to the strong cross relaxation among Er3+ ions. Intense emissions at 1534 rim were also observed in Er3+-doped above mentioned glasses under the excitation of a 978 rim LD laser for the first time. These results have some close relations with the high maximum photon energies of these glasses. The J-O intensity parameters of Er3+-doped CAS, CaAS, CaAG glasses were calculated using the Judd-Ofelt theory, respectively. Then the radiative transition probability A, radiative lifetime T, branching ratio I+ and integrated emission cross-sections of radiative transitions of Er3+ in these glasses were obtained. The stimulated emission cross-sections of Er3+ I13I2++* 115/2 transition in the above mentioned glasses were also obtained. They are 0.580x 10.20, 0.704x1020 and O.332x1020 cm2, respectively. These results indicated these Er3+-doped CAS, CaAS and CaAG glasses are the promising materials for near infrared solid-state laser and Er-doped fiber amplifier(EDFA). The quantum efficiencies of 525 nm, 550 rim and 660 rim emissions of Er3+ ions for Er3+-doped CAS glass under the direct excitation obtained by fluorescence decay measurements and J-O calculation are 17.15%, 1.80%. and 2.62%, respectively. The quantum efficiencies of 525 nm, 548nni and 660 nm emissions of Er3+ ions for Er3+-doped CaAG glass were also obtained and they are 15.39%, 1.80% and 3.33%, respectively. The nonradiative probabilities of 2H112?4S312 transition of Er> for Er3+-doped CAS glass and Er3+-doped CaAG glass were calculated and they are 58166.84 s?and 57340.77 s? respectively. Er> and Yb> co-doped CAS and CaAG glasses were synthesized for the first time. Intense emissions at 1534 rim were observed in these glasses under a 978 nm LD laser for the first time. The results confirmed the efficient Yb>-4 Er> energy transfer. Yb> efficiently sensitized the 1534 rim emission of Er>. These results indicated that these glasses could achieve near infrared laser I oscillation. 4 Intense upconversion emissions were observed in Er> and Yb> co-doped CaAG glass under the excitation of a 978 run LD laser for the first time, while weak upconversion emissions were observed in Er> and Yb> co-doped CAS glass. The main upconversion emissions(blue and red) were attributed to two photons processes. The Er> and Yb> co-doped CaAG glass can be used to detect a 980 rim laser. An intense blue upconversion emission was observed in Tm> and Yb> co-doped CaAG glass under the excitation of a 978 nm LD laser. This blue upconversion emission was attributed to three photons processes. In a word, these new results of this study provide the important and reliable theoretical basis of the design of new materials for optical telecommunication, solid-state laser and upconversio...