Influence of Low Al/Tm Ratio on Spectroscopic Properties and Color Centers in Thulium-Doped Silica Glasses

Inductively coupled plasma atomic emission spectroscopy (ICP-AES) was used to measure the actual Tm and Al element content in glass samples. The absorption spectrum was tested using a spectrophotometer (Perkin Elmer Lambda 950) with a wavelength range of 200-2000 nm, a scanning step size of 1 nm, and a glass thickness of 2 mm.

The fluorescence spectrum of the glass sample was tested using a high-resolution fluorescence spectrometer (FLS920) with an excitation source of 793 nm laser diode. The fluorescence lifetime decay curve was tested using FLS1000 fluorescence spectrometer, with a 793 nm pulse laser as the excitation source and a pulse width of 4 µ s. The Fourier transform infrared spectrometer (Nicolet 6700) was used to measure the infrared transmittance spectrum of the glass sample, with a testing range of 400-4000 cm-1.