Two-dimensional molecular crystals (2DMCs) are emerging ideal materials for future high-performance optoelectronic devices. People are constantly exploring new methods to solve the problem of difficult growth. Here, we design an improved chemical reaction-assisted vertical micro sublimation method based on vertical micro sublimation for the growth of two-dimensional Sb2O3 inorganic molecular crystals for the first time. The saturation absorption characteristics of the self-made Sb2O3 2DMCs were systematically tested, and the Q-switched laser output characteristics of Sb2O3 2DMCs at 1 µm were verified by using Nd: GYAP mixed crystal. The maximum average output power of 231 mW was achieved at 1080.6 nm, corresponding shortest pulse with a duration of 472 ns and maximum pulse repetition rate of 376 kHz. The maximum single pulse energy and the maximum peak power of the laser output were 0.614 µJ and 1.3 W, respectively. The growth of other 2DMCs would be motivated and its potential applications in the field of ultrafast photonics would be expanded with our findings.

It is well known that the laser crystal with mid‐infrared (MIR) broadened and enhanced luminescence is of great significance for various applications, such as atmospheric monitoring, medical surgery and compact, and efficient coherent sources. Herein, we exploit the sensitization and deactivation effects of Yb3+/Dy3+ ions to achieve broadening and enhancement ~3 μm emission of Er3+: 4I11/2→4I13/2 transition in Yb3+/Er3+/Dy3+: PbF2 crystal. The energy transfer (ET) mechanism between Yb3+, Er3+, and Dy3+ was studied. A broadened and enhanced emission with a full width at half maximum of 265 nm was obtained at ~3 μm due to the fact that Er3+ and Dy3+ ions were used as the emission center at the same time. On the one hand, the incorporation of Dy3+ ion can solve the self‐termination bottleneck effect of Er3+ ion, reducing the lifetime of Er3+: 4I13/2 level. On the other hand, Dy3+ ion can simultaneously serve as the emission center of 3 μm, broadening and enhancing the emission of 3 μm. The experiments show that the corresponding ET efficiency Er3+: 4I13/2→Dy3+: 6H11/2 level is as high as 98.0%, indicating that Dy3+ ion can be used as an effective deactivating ion, benefitting to achieve broadening and enhancing MIR emission around 3 μm. Hence, the Yb3+/Er3+/Dy3+: PbF2 crystal is an attractive laser medium for MIR broadband tunable laser applications.

Sm3+/Eu3+: YAlO3 (Sm3+/Eu3+: YAP) single crystal with a size of Ф (25-35) mm × (50-60) mm was successfully grown and analyzed. The use of Sm3+ co-doping to enhance Eu3+: 5D0 → 7F2 orange-red emission has been investigated in the YAP crystal for the first time. Compared with the Eu3+ single-doped YAP crystal, the Sm3+/Eu3+ co-doped YAP crystal possessed a larger fluorescence emission cross section (0.90×10−21 cm2), higher quantum efficiency (78.4%), and comparative fluorescence lifetime (1.74 ms), corresponding to the stimulated emission of Eu3+: 5D0 → 7F2 transition. Moreover, the energy transition efficiency of the energy transition process from the Sm3+: 4G5/2 level to the Eu3+: 5D0 level was calculated to be as high as 47.31%. These results suggest that Sm3+ ion can be used as an efficient sensitizer to enhance the orange-red fluorescence emission and can lead to the expansion of the emission range from 585–640 nm in Sm3+/Eu3+ co-doped YAP crystal.