飞秒激光导致导致在飞秒尺度内的超快退磁过程引起了极大关注，是因为激光泵浦探测提供了一种能够在飞秒尺度对自旋操纵和读出的途径，有望突破现在磁器件的工作响应时间在纳秒尺度的局限。超快退磁的核心问题之一，是研究磁相互作用对自旋角动量耗散和再生快慢的影响。本文研究拟采用全光学飞秒时间分辨的泵浦探测磁动力学（TRMOKE）平台，研究飞秒激光诱导[Co/Pt]n多层膜中的超快退磁动力学行为, 重点是通过研究垂直磁各向异性的大小和层间耦合强度对超快退磁的影响，来理解自旋角动量转移的方式与超快退磁机制的关系，为深入了解超快退磁动力学行为和驱动机制提供更多的实验数据。

One of research frontiers in spintronics is to improve the work speed of the magnetic devices from the limitation of few nanoseceonds. The ultrafast demagnetization induced by femtosecond laser pulse has a great attention. More, the femtosecond laser pump-probe offer a method to manipulate and detect spin at few hundred femtoseconds. As one of key issue for understanding the process of the ultrafast demagnetization, it is interesting and important to explore the relationship between the magnetic interaction and the dissipation and recovary of spin angular momentum. This project will will all optical pump-probe MOKE to probe the dynamics of the ultrafast demagnetization induced by femtosecond pulse in sputter deposited Co/Pt multilayer. The perpendicular magnetic anisotropy in Co/Pt multilay can be tuned by varied number of the period.The interlayer antiferromagnetic exchange can be intruded by a insert Ru layer. By tuning the Ru layer thickness the interlayer antiferromagnetic exchange is varied. We will characterize the process of the ultrafast demagnetization under varied the perpendicular magentic anisotropy and the interlayer exchange. This work It is helpful to understand the process of the spin angular momentum transfer during the ultrafast demagnetization.