Er³⁺‐doped CaF₂ transparent ceramics are promising mid‐infrared gain materials because of their utra‐low phonon energy as well as excellent physical, chemical, and optical properties. However, existing hot‐pressed and hot‐formed CaF₂ ceramics are very difficult to be used in practical applications due to residual pores and weak polycrystallization, respectively. Here, we developed the high quality Er³⁺‐doped CaF₂ transparent polycrystalline ceramic by single crystal ceramization. The sample exhibits obvious polycrystalline structure, good mechanical properties, perfectly transmittance, and excellent mid‐infrared performance, which provides significant and wide‐ranging opportunities for advanced mid‐infrared gain materials.

中文翻译：

---

掺Er3 +的CaF2多晶陶瓷具有完美的透明度，适用于中红外激光

掺Er ^3+的CaF ₂透明陶瓷具有极低的声子能量以及出色的物理，化学和光学特性，因此有望成为中红外增益材料。但是，现有的热压和热成型CaF ₂陶瓷分别由于残留孔和弱多晶性而很难在实际应用中使用。在这里，我们开发了高质量的掺Er ^3+的CaF ₂透明多晶陶瓷通过单晶陶瓷化。该样品表现出明显的多晶结构，良好的机械性能，完美的透射率和出色的中红外性能，这为高级中红外增益材料提供了广泛的机会。