Microcapillaries enable us to simply prepare crystalline perovskites in a microcavity. A precursor solution of methyl ammonium lead bromide (CH3NH3PbBr3) is injected by capillary action into quartz microcapillaries with an inner diameter (ϕ) of 2–40 μm. After drying at 70 °C in the atmosphere, cylindrical crystals are precipitated to fill up the inner cavity of the microcapillary. Under optical pumping, whispering gallery mode lasing depending on ϕ is observed. With reducing ϕ, the mode number and the lasing threshold fluence are found to be decreased. This suggests that the stimulated emission can be enhanced by cavity quantum electrodynamics in CH3NH3PbBr3 crystals which are densely confined in the microcavity. Consequently, the microcapillary with ϕ = 2 μm realizes single-mode lasing at a threshold fluence of 4.7 μJ/cm2.Microcapillaries enable us to simply prepare crystalline perovskites in a microcavity. A precursor solution of methyl ammonium lead bromide (CH3NH3PbBr3) is injected by capillary action into quartz microcapillaries with an inner diameter (ϕ) of 2–40 μm. After drying at 70 °C in the atmosphere, cylindrical crystals are precipitated to fill up the inner cavity of the microcapillary. Under optical pumping, whispering gallery mode lasing depending on ϕ is observed. With reducing ϕ, the mode number and the lasing threshold fluence are found to be decreased. This suggests that the stimulated emission can be enhanced by cavity quantum electrodynamics in CH3NH3PbBr3 crystals which are densely confined in the microcavity. Consequently, the microcapillary with ϕ = 2 μm realizes single-mode lasing at a threshold fluence of 4.7 μJ/cm2.

中文翻译：

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在微毛细管中生长的卤化铅钙钛矿晶体中的回音廊模式激光

微毛细管使我们能够在微腔中简单地制备结晶钙钛矿。甲基铵溴化铅 (CH3NH3PbBr3) 的前体溶液通过毛细管作用注入内径 (φ) 为 2-40 μm 的石英微毛细管中。在大气中 70°C 干燥后，析出圆柱形晶体以填充微毛细管的内腔。在光泵浦下，观察到取决于 ϕ 的回音壁模式激光。随着 ϕ 的减小，发现模式数和激光阈值注量会降低。这表明受激发射可以通过密集限制在微腔中的 CH3NH3PbBr3 晶体中的腔量子电动力学来增强。因此，φ = 2 μm 的微毛细管以 4.7 μJ/cm2 的阈值能量密度实现单模激光。微毛细管使我们能够在微腔中简单地制备结晶钙钛矿。甲基铵溴化铅 (CH3NH3PbBr3) 的前体溶液通过毛细管作用注入内径 (φ) 为 2-40 μm 的石英微毛细管中。在大气中 70°C 干燥后，析出圆柱形晶体以填充微毛细管的内腔。在光泵浦下，观察到取决于 ϕ 的回音壁模式激光。随着 ϕ 的减小，发现模式数和激光阈值注量会降低。这表明受激发射可以通过密集限制在微腔中的 CH3NH3PbBr3 晶体中的腔量子电动力学来增强。因此，φ = 2 μm 的微毛细管以 4.7 μJ/cm2 的阈值能量密度实现单模激光。