论文标题
Znco2O4微量流量中可饱和和反向饱和吸收的脉冲延缓依赖性
Pulse-duration dependence of saturable and reverse saturable absorption in ZnCo2O4 microflowers
论文作者
论文摘要
我们采用开放式Z-SCAN技术来揭示Znco2O4（ZCO）微量流量中的三阶光学非线性。我们的结果表明，可以将跨系统交叉（ISC）寿命用作简单的工具，以证明ZCO中的光学非线性极为对比。超快瞬态吸收测量结果表明，从单线到三重态的ISC发生在5 ps中。对于飞秒激光脉冲，当脉冲持续时间短于ISC寿命时，所有强度都会发生饱和吸收（SA）。相反，当脉冲持续时间比纳秒激发的脉冲持续时间长时，我们会通过激发态吸收在较高强度下从SA到反向SA（RSA）的过渡。我们设想，从SA和RSA中受益，ZCO成为模式锁定和光学限制设备的潜在候选者。
We employed open-aperture Z-scan technique to unveil the third-order optical nonlinearity in ZnCo2O4 (ZCO) microflowers. Our results indicate that intersystem crossing (ISC) lifetime can be used as simple tool to demonstrate remarkably contrasting optical nonlinearity in ZCO. Ultrafast transient absorption measurements reveal that ISC from singlet to triplet state takes place in 5 ps. For femtosecond laser pulses, when the pulse duration is shorter than ISC lifetime, saturable absorption (SA) takes place for all intensities. On the contrary, when the pulse duration is longer than ISC for nanosecond excitation, we observe transition from SA to reverse SA (RSA) at higher intensities via excited-state absorption. We envisage that benefiting from SA and RSA, ZCO emerges as potential candidate for mode locking and optical limiting devices.
