Amplified spontaneous emission from inclusions containing cesium lead bromide in glasses

Cesium lead halide (CsPbX₃, X = Cl, Br and I) perovskite nanocrystals embedded glasses exhibit good optical properties and have potential as gain media. However, origins of the amplified spontaneous emission (ASE) from CsPbX₃ nanocrystals are controversial. Here, it is found that ASE is from CsPbX₃ nanocrystals in inclusions instead of CsPbX₃ nanocrystals dispersed in the glass matrix. Inclusions with various sizes are capable of generating ASE, and ASE of the inclusions can sustain at energy densities as high as several tens of mJ/cm². Thresholds of the fs laser energy densities increase with the increase in fs laser wavelength, and high net optical gain coefficient is obtained.