Novel Er³⁺/Ho³⁺‐codoped glass‐ceramic fibers for broadband tunable mid‐infrared fiber lasers

Abstract

It is well recognized that a widely wavelength‐tunable mid‐infrared (MIR) fiber laser plays an important role in the development of compact and efficient coherent sources in the MIR range. Herein, the optimizing Er/Ho ratio for enhancement of broadband tunable MIR emission covering 2.6‐2.95 μm in the Er3+/Ho3+‐codoped transparent borosilicate glass‐ceramic (GC) fibers containing NaYF4 nanocrystals under 980 nm excitation was investigated. Specifically, the obtained GC fibers with controllable crystallization and well fsd‐maintained structures were prepared by the novel melt‐in‐tube approach. Owing to the effective energy transfer between Er3+ and Ho3+ after crystallization, the 2.7 μm MIR emission was obviously enhanced and the emission region showed a notable extension from 2.6‐2.82 μm to 2.6‐2.95 μm after the addition of Ho3+. Importantly, we conducted a theoretical simulation and calculation related to the MIR laser performance, signifying that the GC fiber may be a promising candidate for MIR fiber laser. Furthermore, the melt‐in‐tube approach will provide a versatile strategy for the preparation of diverse optical functional GC fibers.

Transparent Sol-Gel Oxyfluoride Glass-Ceramics with High Crystalline Fraction and Study of RE Incorporation

“…The melt-quenching (MQ) method has been routinely used to prepare OxGCs that showed excellent optical properties and a significant enhancement of photoluminescence with respect to the precursor glasses. Moreover, the possibility to draw fibers and convert the core into a GC revealed the importance of this method for the preparation of novel devices with new or improved optical efficiencies [15,16,17,18,19,20]. However, the high melting temperatures (1400–1700 °C) greatly affect the fluoride content, limiting the crystal phase content to 10 wt% or less for some crystal phases, such as LaF 3 [7,9,10].…”

Tunable upconversion emission in NaLuF4–glass-ceramic fibers doped with Er3+ and Yb3+

“…This value is similar to that obtained for different GC optical bers. 28,29,46 UC emission. Room temperature UC emission spectra were performed in GC optical bers codoped with 0.5 mol% ErF 3 and 2 mol%YbF 3 , by exciting at 980 nm in resonance with the 4 I 11/2 (Er 3+ ) and 2 F 5/2 (Yb 3+ ) levels.…”

“…Other authors obtained uoride NCs in oxide matrices by the melt-in-tube method using borosilicates cladding and drawing temperatures at which the cladding glass soens but the core is completely melted. [28][29][30][31][32][33] For example, Kang et al 28 obtained NaYF 4 NCs in borosilicate glasses aer heat treatment at 470-500 C and much better ET from Ho 3+ to Er 3+ was observed in the glass-ceramic bers. However, to the best of our knowledge, this method has not still been applied to aluminosilicate compositions because they require the use of SiO 2 cladding and extremely high melting temperatures (1800 C) that can cause strong uorine loss and diffusion phenomena.…”

Intense emission at 2.9 μm from Yb3+/Ho3+ co‐doped TeO2–Ga2O3–ZnO tellurite glasses

“…However, it can not be obtained efficiently due to the lack of absorption bands matched with commercial 808 and/or 980 nm laser diodes (LDs). Therefore, sensitized excitation with rare‐earth and/or semimetal co‐doping such as Tm 3+ /Ho 3+ , Nd 3+ /Ho 3+ , Er 3+ /Ho 3+ , Bi 3+ /Ho 3+ , and other rare‐earth co‐doped glasses have attracted much attention as important matrix materials for 2‐3 μm fiber lasers 2–5 . Moreover, Yb 3+ has a relatively larger absorption cross section at 980 nm, and there is a very effective energy‐transfer process between Yb 3+ and Ho 3+ , which perfectly solves the problem of Ho 3+ lack of absorption band matching with commercial high‐power LDs 6 .…”

“…much attention as important matrix materials for 2-3 μm fiber lasers. [2][3][4][5] Moreover, Yb 3+ has a relatively larger absorption cross section at 980 nm, and there is a very effective energytransfer process between Yb 3+ and Ho 3+ , which perfectly solves the problem of Ho 3+ lack of absorption band matching with commercial high-power LDs. 6 However, the current research on the Yb 3+ /Ho 3+ co-doped system mainly focuses on up-conversion and 2 μm emission.…”