CC BY
10The 30th International Conference on Advanced Laser Technologies ALT'23
LS-P-10
Optical properties of Sm3+ doped chalcogenide glass samples irradiated with S polarized and P polarized light
Yu. Kuzyutkina1, N. Parshina1, V. Kochubey1, E. Romanova1, R. Blagin2, V. Shiryaev2
1- Saratov State University, Astrakhanskaya 83, 410012 Saratov, Russia
2- Devyatykh Institute of Chemistry of High-Purity Substances of RAS,
49 Tropinin Str., 603951 Nizhny Novgorod, Russia
Design of rare earth (RE) doped chalcogenide glasses is a current trend towards creation of fiber lasers operating in mid-infrared spectral range. In this work, optical properties of chalcogenide glasses of the system Ge-Ge-As-Se doped with samarium ions (Sm3+) have been studied near their fundamental absorption band (FAB) edge. The glasses were obtained by direct melting of especially pure substances Ge, As, Se - 6N, Ga -7N, Sm - 3N [1]. Content of Sm3+ in the glasses (0, 750, 1700 ppm) was determined by the Inductively Coupled Plasma - Atomic Emission Spectroscopy [2]. The presence of crystals and heterophase inclusions of micron size was analyzed by optical microscopy.
Transmittance and reflectance spectra of the glasses shaped as thin disks were measured by using the Perkin Elmer Lambda 950 spectrometer in the wavelength range of 0.5-1.8 ¡j.m. The glass samples were irradiated by linearly polarized light of two orthogonal polarizations (P- polarized and S- polarized light). In accordance with the Fresnel equations, in the transmittance spectra (Fig.la), the curves obtained with P- polarized light are located above the curves obtained with S- polarized light in the Sm3+ absorption bands and between the bands. Noises in the wavelength range of 0.8-0.9 ^m are associated with switching the operation mode of the spectrophotometer.
Spectral dependencies of attenuation and refraction coefficients (Fig.1b,c), as well as optical bandgap energy (Eg) and Urbach energy (Eu) were calculated by using the approach described in [3].
F— p 0 • / — so / -P 750 / -S 750 Y! W7 P 1700 S 1700
-PO
-SO
- P 750 /
- S 750 /
P 1700 /
s noojf
\\ -/K
0.8
1.0 1.2
wavelength, um a
1.4
1.0 1.2 1.4 1.6
photon energy, eV
b
Fig. 1 Spectral dependencies of glass samples transmittance (a) measured with an integrating sphere; logarithm of attenuation coefficient (b) obtained from measurements with an integrating sphere; refractive index (c) obtained from measurements with a collimated light beam.
1.0 1.2 1.4
wavelength, (tm c
Dependence of ln(a) on the photon energy hv (Fig.lb) shows that the absorption bands of Sm3+ are located at the weak absorption tail (hv < 1.4 eV) of the glass FAB edge. Magnitude of Eg corresponds to the high frequency edge of the linear part of the function ln(a) = f(hv) at a = 103 cm-1. For Eu evaluation, the derivatives S(hv) = d(ln(a))/d(hv) were calculated. For all the samples, the values Eg ~ 1.93 eV and Eu ~ 0.073 eV have been obtained. The ranges of anomalous dispersion within the Sm3+ absorption bands in Fig.1c are clearly seen.
In analysis of the results presented here, specific structural and electronic properties of chalcogenide glasses are to be taken into consideration. This work was supported by the Russian Science Foundation (RSF) under Grant 21-13-00194.
[1] V.S. Shiryaev, E.V. Karaksina, A.P. Velmuzhov, et.al. Preparation and investigation of GaxGe25Asi5Se6o-x (x=1^5) glasses, Opt. Mat. 67, 38-43 (2017)
[2] I.I. Evdokimov, D.A. Fadeeva, A.E. Kurganova, V.S. Shiryaev, V.G. Pimenov, E.V. Karaksina. J. Analyt. Chem., 7 (7), 869-877 (2020).
[3] Yu.S. Kuzyutkina, E.A. Romanova, V.I. Kochubey, V.S. Shiryaev. Opt. i spektr., 117 (1), 60-66 (2014). (in Russian).
