Patent ID: 9029068
Filing Date: 2015-05-12
Classification: G02B,G11B,G11C,H01L,H01S

Abstract:
1. A phase change switching method for causing phase change in a phase change recording film by irradiating a femtosecond pulse laser onto a phase change recording film which is Ge—Sb—Te material; wherein one femtosecond pulse is split into pulse trains each having multiple pulses and the pulse trains are irradiated by matching a time interval of the multiple pulses with a time period of lattice vibration of a material constituting the phase change recording film and by adjusting an intensity of a second pulse of the multiple pulses after the time interval, thereby inducing non-thermal phase change in the phase change recording film, said non-thermal phase change being defined as a change confirmed by measuring the A the time interval of the pulse trains corresponds to a characteristic vibration frequency in a phonon mode that manifests prominently after the phase change from amorphous to crystalline or from crystalline to amorphous states, wherein the time interval of the pulse trains is set in a range of 270 fs to 278 fs for phase change from amorphous to crystalline states, and is set at around 263 fs for phase change from crystalline to amorphous states.