[19a-P5-1~6] 16.1 Fundamental properties, evaluation, process and devices in disordered materials

[19a-P5-2] Preparation of low-phonon energy CaO-Al₂O₃-Ga₂O₃ glasses

〇Kaito Noda¹, Takenobu Suzuki¹, Yasutake Ohishi¹ (1.Toyota technol. Inst.)

Keywords:oxide glass, phonon energy, non-radiative relaxation

Fiber lasers have an issue of reduction in efficiency due to non-radiative relaxation. The non-radiative relaxation is dominantly caused by multiple phonon relaxation by coupling of rare-earth ion and vibration of the host glass. Multiple phonon relaxation is remarkable in high phonon energy host glass. CaO-Al₂O₃-Ga₂O₃ glass has been prepared using intermediate and network modifier without any conventional network former. CaO-Ga2O3 glass has the highest wavenumber of the Raman peak and non-radiative relaxation rate lower than conventional oxide glass. This indicates that the effective phonon energy of CaO-Ga₂O₃ glass is that of enough low to be used as an efficient laser medium.