Role of Aluminum in Ytterbium–Erbium Codoped Phosphoaluminosilicate Optical Fibers

Energy transfer up-conversion in Tm3+-doped silica fiber

“…A York S14 index profiler was used to obtain the refractive index profiles of the fibre samples and the Al 2 O 3 concentrations were estimated from these profiles since Al 2 O 3 has been shown to increase the optical index of silica by 2.3×10 -3 per mol % [14]. It was assumed that the concentration of Tm 3+ did not contribute significantly to the index difference.…”

Structural and optical properties of Al-Tb/SiO2 multilayers fabricated by electron beam evaporation

“…In that case, and considering that the rest of the oxygen atoms are bound to Tb ones, we estimate that there will be a minimum of 45% of Tb atoms in the form of Tb 2 O 3 . Even though the possibility of having Al-Tb-O ternary compounds cannot be ruled out 18,19 because Al and Tb atoms are homogeneously distributed in the Al/Tb/Al stack (as observed by TEM measurements). For the sample with no Al, the situation is much different: the oxygen-to-silicon ratio is exactly 2.0, indicating that no extra oxygen is added to the Tb layers.…”

“…In the literature, and in combination with SiO 2 , aluminum has been widely employed for dispersing RE ions and thus allows for a higher RE incorporation without clustering. 18,19 Different methods have been employed to combine these materials, being ion implantation, 16 thermal evaporation in effusion cells, 20 or plasma-enhanced chemical-vapor deposition 21 the most used ones. In a previous publication, some of the current authors reported the fabrication of Tb doped SiO 2 by means of chemical vapor deposition.…”

Effect of P5+ on spectroscopy and structure of Yb3+/Al3+/P5+ co-doped silica glass

“…The broad band at 1000-1250 cm À 1 is ascribed to the contribution from Si-O-Si, Si-O-Al, P-O-Al, P-O-P, and Si-O-P linkages [1,24,35], and the sharp band at 1320 cm À 1 in sample AP4 is derived from P¼O stretching vibration [23,35]. Moreover, the characteristics of the broad band at 1000-1250 cm À 1 reveal the presence of AlPO 4 -like units in the glass with Al 3 þ /P 5 þ codoping [23,24], and the peak at 1320 cm À 1 indicates the presence of PO 4 units in glass with molar ratio of P 5 þ /Al 3 þ 41 [23,36].…”