An experimental system has been assembled to measure the absolute values of the Raman gain spectrum for millimeter-thick glass samples. Results are reported for two new oxide glasses with Raman gain coefficients as much as 30 times larger than that of fused silica and more than twice its spectral coverage.

In this study we report the physical properties and spontaneous Raman scattering spectra of nine oxide tellurite and fluorotellurite glasses from three glass systems—sodium–zinc–tellurite (TZN), tungsten–tellurite, and fluorotellurite. Raman gain and surface damage threshold at 1064 nm are also shown for a selection of these glasses, which all exhibited high gain and damage resistance. Raman gain spectra were directly measured and accurately calculated for selected TZN and fluorotellurite glasses after Fresnel, internal solid angle, and Bose–Einstein corrections. The calculated gain showed good fits to the Raman gain measurements made using a calibrated nonlinear optics apparatus. Infrared and UV‐Vis absorption spectra, characteristic temperatures obtained by differential thermal analysis, densities acquired by the Archimedes principle and refractive indices measured by spectroscopic ellipsometry are also given. The ternary systems TeO2–WO3–Bi2O3 and TeO2–Na2O–ZnF2 and the quaternary system TeO2–Na2O–ZnO–PbO show promise as Raman amplifiers as they are relatively easy to draw into optical fiber and to these authors' knowledge, this is the first time Raman gain has been presented on halide containing tellurite glasses. The oxyfluoride system studied here, TeO2–Na2O–ZnF2, exhibited a dependence on the peak Raman intensity with ZnF2 addition. Calculations of preform geometry for mono‐ and multimode guidance and stresses in similar and dissimilar (core suction) core–clad pairs are shown. Dispersion in the mid‐infrared and initial fiber drawing studies are also reported with fibers showing reasonable unclad losses.

Several different compositions of tellurium-thallium oxide glasses were fabricated and tested for their Raman gain performance. The addition of PbO to the glass matrix increased the surface optical damage threshold by 60-230%. The maximum material Raman gain coefficient experimentally obtained was (58 +/- 3) times higher than the peak Raman gain of a 3.18 mm thick Corning 7980-2F fused silica sample (Deltanu = 13.2 THz). The highest peak in the Raman gain spectrum of the tellurium-thallium glass is attributed to the presence of TeO3 and TeO3+1 structural units with thallium ions in the vicinity at a frequency shift near 21.3 THz.

Disagreements on the Raman gain response of different tellurite-based glasses, measured at different wavelengths, have been recently reported in the literature. In order to resolve this controversy, a multi-wavelength Raman cross-section experiment was conducted on two different TeO2-based glass samples. The estimated Raman gain response of the material shows good agreement with the directly-measured Raman gain data at 1064 nm, after correction for the dispersion and wavelength-dependence of the Raman gain process.

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