Energy transfer and energy level decay processes in Tm3+-doped tellurite glass

Abstract

Continuous-annealing method for producing a flexible, curved, soft magnetic amorphous alloy ribbon J. Appl. Phys. 111, 07A309 (2012) Fabrication of nanoscale glass fibers by electrospinning Appl. Phys. Lett. 100, 063114 (2012) Thermodynamic, Raman and electrical switching studies on Si15Te85-xAgx (4 ≤ x ≤ 20) glasses J. Appl. Phys. 111, 033518 (2012) Synthesis of single-component metallic glasses by thermal spray of nanodroplets on amorphous substratesThe primary excited state decay and energy transfer processes in singly Tm 3þ -doped TeO 2 :ZnO:Bi 2 O 3 :GeO 2 (TZBG) glass relating to the 3 F 4 ! 3 H 6 $1.85 lm laser transition have been investigated in detail using time-resolved fluorescence spectroscopy. Selective laser excitation of the 3 H 4 manifold at 794 nm, the 3 H 5 manifold at 1220 nm, and 3 F 4 manifold at 1760 nm has established that the 3 H 5 manifold is entirely quenched by multiphonon relaxation in tellurite glass. The luminescence from the 3 H 4 manifold with an emission peak at 1465 nm suffers strong suppression due to cross relaxation that populates the 3 F 4 level with a near quadratic dependence on the Tm 3þ concentration. The 3 F 4 lifetime becomes longer as the Tm 3þ concentration increases due to energy migration and decreases to 2.92 ms when [Tm 3þ ] ¼ 4 mol. % as a result of quasi-resonant energy transfer to free OH À radicals present in the glass at concentrations between 1 Â 10 18 cm À3 and 2 Â 10 18 cm À3 . Judd-Ofelt theory in conjunction with absorption measurements were used to obtain the radiative lifetimes and branching ratios of the energy levels located below 25 000 cm À1 . The spectroscopic parameters, the cross relaxation and Tm 3þ ( 3 F 4 ) ! OH À energy transfer rates were used in a numerical model for laser transitions emitting at 2335 nm and 1865 nm. V C 2012 American Institute of Physics. [http://dx.

Mechanical and ∼2μm emission properties of Tm3+-doped GeO2–TeO2 (or SiO2)–PbO–CaO glasses

“…The spectroscopic properties of Tm-doped silicate, fluorophosphate, germanate, and tellurite glasses or crystals have been studied for decades [1][2][3][4][5]. Most studies have been focused on the development of fiber laser systems capable of delivering efficient high-power output at a wavelength of 2 lm because of its applications in the area of remote sensing, medical surgery, environmental sensing, and light sources for efficient mid-IR generation [6][7][8][9].…”

Dual-band Tm3+-doped tellurite fiber amplifier and laser at 1.9 μm and 2.3 μm

“…The rate equations for the population densities n 1 , n 2 , n 3 , n 4 (normalized to the concentration of Tm 3+ ions in the core N Tm  = 5·10 19  cm −3 ) are given by 29 :where τ 4 , τ 4 R and τ 4 NR are the total, radiative and non-radiative lifetimes of level 4, respectively ( τ 4  = 0.3 ms 20,34 , τ 4 R  = 0.4 ms 29 , τ 4 NR  = (1/ τ 4  − 1/ τ 4 R ) −1  = 1.2 ms); τ 3 is the total (non-radiative) lifetime of level 3 ( τ 3  = 0.13 μs 20,34 ); τ 2 is the total lifetime of level 2 ( τ 2  = 3 ms 20,24,29 ); β 4y is the branching ratio from level 4 to level y  = 1, 2, 3 ( β 41  = 0.9, β 42  = 0.07, β 43  = 0.03 29 ); K CR is the coefficient of cross-relaxation ( K CR  = 1000 s –1   29 ), W xy are the stimulated rates. Stimulated rates by hydroxyl groups were neglected due to their extremely low concentration in the produced sample.…”

“…Therefore, when developing novel tellurite glasses and fibers for generation at 2.3 μm, more stringent conditions should be imposed on the quality of the samples in comparison with the samples for generation of only about 2 μm. It is desirable to produce a high-quality fiber with minimum possible background loss, as well as with a low concentration of hydroxyl groups (which can effectively reduce the lifetime of the excited state 29 ). In addition, it is necessary to carefully choose the concentration of Tm 3+ ions.…”

Nonsilica Oxide Glass Fiber Laser Sources: Part I

“…These ions could decrease the fluorescence intensity and ultimately lead to the deterioration of the laser performance and even inhibit the laser output [75]. In the tellurite glass system, significant results of RE ion emission in the mid-IR region have been reported from Tm 3+ ,Ho 3+ and Er 3+ [76][77][78][79][80][81][82]. Nonsilica Oxide Glass Fiber Laser Sources: Part I http://dx.doi.org/10.5772/intechopen.73488 Thulium (Tm) is an ideal choice for the realization of glass lasers in the~2 μm wavelength range, since it displays one of the broadest fluorescence bands among RE ions [83] due to the transition Tm 3+ : 3 F 4 !…”