The rapid development of modern information technology demands more and more data storage capacity and storage speed. However, with the development of storage technology toward ultra-high density and super-high speed, on the one hand, the magnetic recording density has also approached the superparamagnetic limit (100 Gbpsi). To further improve the recording density, a recording medium with high coercivity must be adopted, but the current magnetic head can not provide a writing magnetic field which can overcome the high coercivity. On the other hand, the magnetic recording speed has slowed down due to the magnetization reversal speed. Therefore, the development of new ultra-high density, ultra-high speed recording technology has become a new challenge in the field of modern information technology. The realization of femtosecond laser ultrafast thermally induced all-optical magnetization switching paved the way to develop the ultra-high density ultrafast-rate recording material, and thus became a hot topic of magnetic information storage research. The new magnetic recording technique uses femtosecond linearly polarized light to heat magneto-optical material GdFeCo ferromagnetic thin films directly to achieve all-optical magnetization switching, which is based on spin exchange between ferromagnetic lattices and occurs in picosecond ultrafast time scale. It is considered to be an important achievement in the development of a new generation of ultra-high-speed storage technology because of its simple structure, low cost, and high storage speed. However, in order to promote the realization of the new all-optical magnetic recording technology, it is necessary not only to understand the physical mechanism of the origin of the ultrafast thermally induced magnetization switching of femtosecond laser, but also to clarify the specific realization process of the magnetization switching, and to clarify the realization conditions and influencing factors of the all-optical magne-tization switching. Requirements for structural parameters and material properties of the materials used, as and the pulse width and flunence, as well as the effects of these material parameters and laser conditions on the switching speed of ultrafast thermally induced all-optical magnetization switching. Only by understanding the mechanism of ultrafast thermally induced magnetization switching and the influencing factors of all-optical magne-tization switching can we really promote the development of new ultra-high density and ultra-high speed all-optical magnetic recording technology. Here the technical characteristics and physics mechanism of ultrafast thermal induced magnetization switching for rare earth-transition metal GdFeCo ferrimagnetic films are discussed in detail. The requirements of material properties and pump laser for ultrafast thermal induced magnetization switching are further studied. Finally, an obvious barrier to high density recording is pointed for the use of large amorphous structures, and the solution to the issue is further proposed. The results are expected to help to develop new ultrahigh-density and ultrafast-rate recording material and technology. © 2019, Materials Review Magazine. All right reserved.
