[4] Wilhelm S. Perspectives for upconverting nanoparticles[J]. ACS Nano, 11, 10644-10653(2017).
[21] Xie Y L, Shen B, Zhou B S et al. Progress in research on rare-earth upconversion luminescent nanomaterials and bio-sensing[J]. Chinese Journal of Lasers, 47, 0207017(2020).
[22] Li H, Cui Z Z, Chen W Q et al. Research progress on rare earth doped fluoride multiband upconversion laser[J]. Laser & Optoelectronics Progress, 57, 071601(2020).
[60] Chen Y J, Lin Y F, Huang J H et al. Research progress in 1550-nm all-solid-state lasers based on Er3+-doped crystals[J]. Chinese Journal of Lasers, 47, 0500018(2020).