Er³⁺and Yb³⁺concentration effect in the spectroscopic properties and energy transfer in Yb³⁺/Er³⁺codoped tellurite glasses

Abstract

Spectroscopic properties of Yb3+/Er3+ codoped tellurite glasses as a function of Er3+ and Yb3+ concentration have been investigated. Under 970 nm excitation three strong up-conversion emission bands centred at 525, 546 and 656 nm were observed, and the characteristic near infrared emission band was centred at 1.53 µm. With fluorescence and radiative lifetime the quantum efficiency (QE) of infrared (1.53 µm) and visible upconversion (546 and 660 nm) emissions was calculated. The maximum stimulated emission cross section for 4I13/2 → 4I15/2 transition of Er3+ is 9.7 × 10−21 cm2 for 3/0.5 mol%. The energy transfer (ET) efficiency from Yb3+ to Er3+ (4F5/2) + (4I15/2) → (4 F7/2) + (4I13/2) was calculated, being the maximum ET of 69% for 0.5 mol% of Er3+ with 4.5 mol% of Yb3+. The results indicate that both ET and QE depend mostly on Er3+ rather than on Yb3+ concentration.

Surfactant effect on the upconversion emission and decay time of ZrO2:Yb-Er nanocrystals

“…In the ET process, decay time depends on the intermediate state of decay, which for Yb is much larger than 4 I 11/2 of Er [36]. In addition, it has been shown that the presence of Yb avoids clustering of the Er ion, enhancing all spectroscopic properties [37]. Yb-Er-codoped nanocrystals also present an increment on the effective decay time with the use of surfactant.…”

Mixing up-conversion excitation behaviors in Er3+/Yb3+-codoped aluminum germanate glasses for visible waveguide devices

“…Fig. 3 exhibits the energy level diagram of Er 3+ and Yb 3+ in NMAG glasses [42][43][44][45][46][47]. Under low-power excitation of 974 nm laser, for 4 F 9/2 → 4 I 15/2 transition, Er 3+ ions are excited to the 4 I 11/2 level by the ground state absorption (GSA) and the energy transfer (ET) from Yb 3+ , and then partly relax nonradiatively to the 4 I 13/2 level.…”

Optical properties of Nd3+-doped and Er3+–Yb3+ codoped borotellurite glass for use in NIR lasers and fiber amplifiers

“…This feature has the effect of both increasing the efficiency of the Yb 3+ to Er 3+ energy transfer and reducing the concentration quenching of the Er 3+ ions [11,12]. Moreover, the codoping of Yb 3+ ions with Er 3+ ions in different glasses has yielded enhanced luminescence properties of the Er 3+ ions [13]. So, an important need for rigorous investigation of the codoped Er 3+ Yb 3+ ions in various glass matrices exists, with a view to achieving unprecedented results in telecommunication technology [10,14,15].…”