Experimental Characterization of Transition Noise in HAMR

Due to the sensitivity of the write process to temperature variations and laser position alignment, transition noise in heat-assisted magnetic recording (HAMR) may exhibit characteristics that are significantly different from those of conventional magnetic recording. In this work, statistical properties of transition noise in HAMR are investigated using real data taken off a spin stand. The Karhunen Loeve (K-L) expansion method is applied to the read waveforms corresponding to a pseudorandom bit pattern written at varying locations of a disk.