Dual-pulse excitation method for ultra-fast, super-resolution all-optical magnetic recording

A dual-pulse excitation method for ultra-fast, super-resolution all-optical magnetic recording, comprising the steps of:

• providing a first excitation pulse and a second modulation pulse, the first excitation pulse and the second modulation pulse being both femtosecond laser pulses, and the energy density of the second modulation pulse is less than that of the first excitation pulse;
• and
• focusing the first excitation pulse and the second modulation pulse, and then radiating the two pulses in sequence to a magneto-optical recording medium, so that an area of the magneto-optical recording medium irradiated by a laser pulse spot undergoes all-optical magnetization reversal;
• the magneto-optical recording medium being a magneto-optical material capable of realizing opto-magnetic reversal by a single laser pulse, the minimum energy density threshold required for realizing all-optical magnetization reversal by a single laser pulse being F, and the energy density of the second modulation pulse<Threshold F≤the energy density of the first excitation pulse;
• the critical time interval between two magnetic reversals of the magneto-optical material being Δtc, and Δtc≤the successive incidence time interval between the first excitation pulse and the second modulation pulse<1 nanosecond;
• the focal spot of the first excitation pulse and the focal spot of the second modulation pulse having an overlapping portion and a non-overlapping portion, and when the second modulation pulse being radiated to the overlapped portion afterwards, the undissipated part of the energy generated by the radiated first excitation pulse at the beginning being remained in the overlapping portion;
• the overlapping portion of the focal spot of the first excitation pulse returning to the initial magnetic state after two magnetization reversals, and the non-overlapping portion of the focal spot of the first excitation pulse retaining one magnetization reversal to form a magnetic recording bit.