We report on enhanced nonlinear optical absorption and optical limiting in β-MnO₂ sponge-like nanowire network decorated with Ag nanoparticles excited by nanosecond laser. A simple two-step process is used to prepare the samples. The structure, morphology and the elemental analysis of the prepared samples are studied using x-ray diffraction, field emission scanning electron microscopy and energy-dispersive x-ray spectroscopy. Nonlinear optical absorption properties of the samples in solution is studied using the open aperture Z-scan technique employing 5 ns laser pulses at 532 nm. Nonlinear transmission measurements show that β-MnO₂ exhibit weak saturable absorption at low fluence and large optical limiting at high fluence, while upon decoration with Ag particles, Ag/β-MnO₂ shows strong saturable absorption at low fluence and enhanced optical limiting at higher fluence with an optical limiting threshold value three times lower than that of bare β-MnO₂ nanowires. The results indicate that these materials are potentially useful for constructing saturable absorbers and optical limiters.

我们报告了 β-MnO ₂海绵状纳米线网络中增强的非线性光学吸收和光学限制，该网络装饰有由纳秒激光激发的 Ag 纳米粒子。使用简单的两步过程来制备样品。使用 x 射线衍射、场发射扫描电子显微镜和能量色散 x 射线光谱研究制备的样品的结构、形貌和元素分析。使用采用 532 nm 的 5 ns 激光脉冲的开孔 Z 扫描技术研究溶液中样品的非线性光学吸收特性。非线性透射测量表明，β-MnO ₂在低通量下表现出弱的饱和吸收，在高通量下表现出较大的光学限制，而在用 Ag 颗粒装饰后，Ag/β-MnO_图2显示了在低能量密度下的强饱和吸收和在较高能量密度下增强的光学限制，其光学限制阈值比裸β-MnO ₂纳米线低三倍。结果表明，这些材料可用于构建可饱和吸收器和光学限制器。