Impact of Background Interference on Signal-to-Noise Ratio in Heat-Assisted Magnetic Recording

We discuss background interference (BGI) arising from the read-back of preexisting data and adjacent tracks on a recording medium. A signal-to-noise ratio analysis is used to measure the impact of BGI in heat-assisted magnetic recording in a spin-stand tester. The signal-to-noise ratio for a data track with an alternating field background was compared to a data track written over a pair of background tracks. We considered the effect of background track offsets: the distance between the background and data tracks. BGI, which depends on the background track offset, can degrade read-back performance. The dibit extraction technique is able to separate the linear dibit response and the BGI in the read-back waveform.