• correlation of the effect of modifying the structure of antimony-germanate
glasses on the shape of the luminescence while maintaining their optical and
thermal properties;
• obtaining a plasmonic effect by thermochemical reduction of silver ions in
antimony-germanate glasses and glass fibers doped with lanthanides,
• analysis of correlation of structural changes of germanate glasses for detailed
characterization of luminescence properties.
14.2 The Effect of the Structure of Antimony-Germanate
Glasses Modification on the Luminescent Properties
According to the mentioned above assumptions for photonic applications, the
fabricated glass should be characterized by low phonon energy and high thermal
stability. Thus, influence of the substitution of germanium oxide with antimony
oxide on the spectroscopic and thermal properties of glass with chemical composition (50 − x)Sb 2 O 3 –xGeO 2 –45SiO 2 –5Al 2 O 3 doped with Sm
3+ ions with a molar
content of 0.5% was analyzed [28]. In this case, the content of germanium oxide
was changed from 0 to 45 mol%. Introduction of a samarium ion into the matrix
allowed obtaining a strong visible emission of a characteristic orange color, due to
high emission efficiency resulting from a large energy gap (ca. 12,000 cm
−1 )
between the
4 G 5/2 metastable level, and multiplet located below the
6 H J , an ion that
is readily used in phosphors [29].
The reason is that Sm
3+ ion has absorption bands located at 405 and 470 nm
wavelengths, which can be efficiently excited by high power lasers diodes. As a
result of excitation in the spectra of the presented glasses, four characteristic emission bands have been observed at wavelengths of 566, 603, 647, and 709 nm corresponding to radiative relaxation from the level
4 G 5/2 to the lower sub-levels of the
6 H J multiplet where J = 5/2, 7/2, 9/2, and 11/2 (Fig. 14.1). Analysis of the intensity
changes of individual luminescence bands, as a function of the content of GeO 2
oxide, shows that all fabricated glass samples were characterized by the strongest
luminescence at 603 nm. In contrast, the maximum level of luminescence has been
achieved for glasses at 15 mol% Ge 2 O content, and a minimum at 30 mol%.
Samarium ions belong to the group of lanthanides characterized by radiative transitions that depend on the environment (structure) in which they are found.
According to the theory of the selection rule DJ = 0, ±1, the first two bands are
described as magnetic-dipolar transitions (MD) as well as partially electro-dipole
transitions, while the second two are described as electro-dipole transitions (ED).
Analyzing the ratio of the transition intensity
4 G 5/2 !
6 H 9/2 (ED) to the transition
intensity
4 G 5/2 !
6 H 5/2 (MD) the value was greater than 1, which proves that all the
samples produced can be characterized by asymmetry in structure around the
Sm
3+ ion.
430
J. Zmojda et al.
glasses on the shape of the luminescence while maintaining their optical and
thermal properties;
• obtaining a plasmonic effect by thermochemical reduction of silver ions in
antimony-germanate glasses and glass fibers doped with lanthanides,
• analysis of correlation of structural changes of germanate glasses for detailed
characterization of luminescence properties.
14.2 The Effect of the Structure of Antimony-Germanate
Glasses Modification on the Luminescent Properties
According to the mentioned above assumptions for photonic applications, the
fabricated glass should be characterized by low phonon energy and high thermal
stability. Thus, influence of the substitution of germanium oxide with antimony
oxide on the spectroscopic and thermal properties of glass with chemical composition (50 − x)Sb 2 O 3 –xGeO 2 –45SiO 2 –5Al 2 O 3 doped with Sm
3+ ions with a molar
content of 0.5% was analyzed [28]. In this case, the content of germanium oxide
was changed from 0 to 45 mol%. Introduction of a samarium ion into the matrix
allowed obtaining a strong visible emission of a characteristic orange color, due to
high emission efficiency resulting from a large energy gap (ca. 12,000 cm
−1 )
between the
4 G 5/2 metastable level, and multiplet located below the
6 H J , an ion that
is readily used in phosphors [29].
The reason is that Sm
3+ ion has absorption bands located at 405 and 470 nm
wavelengths, which can be efficiently excited by high power lasers diodes. As a
result of excitation in the spectra of the presented glasses, four characteristic emission bands have been observed at wavelengths of 566, 603, 647, and 709 nm corresponding to radiative relaxation from the level
4 G 5/2 to the lower sub-levels of the
6 H J multiplet where J = 5/2, 7/2, 9/2, and 11/2 (Fig. 14.1). Analysis of the intensity
changes of individual luminescence bands, as a function of the content of GeO 2
oxide, shows that all fabricated glass samples were characterized by the strongest
luminescence at 603 nm. In contrast, the maximum level of luminescence has been
achieved for glasses at 15 mol% Ge 2 O content, and a minimum at 30 mol%.
Samarium ions belong to the group of lanthanides characterized by radiative transitions that depend on the environment (structure) in which they are found.
According to the theory of the selection rule DJ = 0, ±1, the first two bands are
described as magnetic-dipolar transitions (MD) as well as partially electro-dipole
transitions, while the second two are described as electro-dipole transitions (ED).
Analyzing the ratio of the transition intensity
4 G 5/2 !
6 H 9/2 (ED) to the transition
intensity
4 G 5/2 !
6 H 5/2 (MD) the value was greater than 1, which proves that all the
samples produced can be characterized by asymmetry in structure around the
Sm
3+ ion.
430
J. Zmojda et al.