∼ 1.2 μm near-infrared emission and gain anticipation in Ho ³⁺ doped heavy-metal gallate glasses

Ho³⁺-doped low-phonon-energy heavy-metal gallate glasses (LKBPBG) have been prepared and efficient 1.199 μm emission originating from the ⁵I₆ → ⁵I₈ radiative transition has been observed under 900 nm excitation. The spontaneous emission probability and the maximum stimulated emission cross-section were derived to be 294.31 s^{- 1} and 3.46 × 10^{- 21} cm², respectively. The ratio of quantum yields between ∼ 1.2 and ∼ 2.0 μm emissions was identified to be 16%, demonstrating that the ⁵I ₆ → ⁵I₈ transition is favorable for optical amplification. The maximum gain coefficient of 1.84 dB/cm at 1.199 μm wavelength was anticipated in the ideal status. These results indicate that the Ho³⁺-doped LKBPBG glasses have a promising potential for the development of ∼ 1.2 μm signal amplifier devices.