By using a luminescence spectrometer and femtosecond laser, we have investigated the specific optical properties and excitation mechanism of ZnO clusters with one-photon and two-photon excitations. When the excitation wavelength was chosen to be 360 nm, the strongest luminescence intensity was observed. However, the luminescence intensity decreased gradually and the emission peak was red shifted slowly with increasing excitation wavelength (from 360 to 400 nm). When the excitation wavelength was chosen to be 780 nm, the luminescence intensity increased nonlinearly with increasing excitation intensity. What is even more interesting is that ZnO clusters could be used in the imaging of living cells under two-photon excitation, implying the potential applications for the optical properties of ZnO clusters in the field of biophotonics.

通过使用发光光谱仪和飞秒激光器，我们研究了具有单光子和双光子激发的 ZnO 簇的特定光学性质和激发机制。当激发波长选择为 360 nm 时，观察到最强的发光强度。然而，随着激发波长的增加（从 360 到 400 nm），发光强度逐渐降低，发射峰缓慢红移。当激发波长选择为 780 nm 时，发光强度随着激发强度的增加呈非线性增加。更有趣的是，ZnO 簇可用于双光子激发下的活细胞成像，这意味着 ZnO 簇的光学特性在生物光子学领域的潜在应用。