Resolved discrepancies between visible spontaneous Raman cross-section and direct near-infrared Raman gain measurements in TeO2-based glasses

Abstract

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.

Enhanced Raman gain coefficients and bandwidths in P2O5 and WO3 added tellurite glasses for Raman gain media

“…Large resonant contributions were observed in the Raman spectral shape and intensity of TW15 glass at 532 and 633 nm in agreement with the results of Rivero et al 8 The bandwidth of TW15 glass decreased with the increase in excitation wavelength ͓Fig. 1͑a͔͒.…”

“…The resonant scattering at these wavelengths may overestimate the real scattering cross sections of the present tellurite glasses at the telecommunications window, 6,8 where the end use of these materials are expected. Figure 1 shows the reduced spectra, normalized to silica, 4 of TW15 and 68TeO 2 -3.5BaO -10.5SrO -8Nb 2 O 5 -10WO 3 ͑TBSNW͒ glasses excited at 532 and 633 nm.…”

“…The samples were excited using ϳ150 mW lasers of wavelengths of 532 and 633 nm. A reason for Raman scattering experiments at these two wavelengths was to evaluate the resonant scattering contribution in the present glasses as noted by Rivero et al 8 for TW15 glass. The spectra were recorded in the quasibackscattered mode with v/v polarization.…”

Gain flattened fiber raman amplifiers by tailoring raman amplification bandwidth of tellurite glasses

“…Knowledge of bandgap is required to evaluate the Raman scattering intensity of glasses for their use in communication bands. 19,32 If the Raman intensity is evaluated by exciting the samples near the band edge or in the band tail, the resonantly scattered photons leads to an overestimation of gain coefficient. 19,32 When the glasses are excited at wavelengths far from band edges resonant scattering is not observed.…”

Raman scattering characteristics of WO 3 and P 2 O 5 doped TBSN glasses: a new gain medium for broadband fiber Raman amplifiers

“…The silica and germanium-doped silica fibers are currently used as Raman gain materials in telecom industry, however, these fibers have very low Raman gain response and limited usable spectral bandwidth of around 5THz for single pump excitation. This has led to research focused on new Raman gain materials, typically multi-component tellurite glasses in the search for compositions to enhance either Raman gain coefficients, bandwidths, or both [14][15][16][17].…”