Nonlinear timing shift in high frequency magnetic recording determined with time resolved Kerr microscopy

As we move to higher data rates and higher areal densities, nonlinear effec ts start to determine the data patterns written on a hard disk. In this con text it is necessary to develop methods that can help to determine the orig in of nonlinear effects, e.g., that can help to distinguish between nonline ar effects caused by areal density from transient effects caused by high da ta rates. In this article we concentrate on the latter and show data for no nlinear timing shift measured directly on the air bearing surface of record ing heads by means of time resolved magneto-optical Kerr microscopy. We com pare the data to a simple t/(t + tau) model for the head field rise time. ( C) 1999 American Institute of Physics. [S0021-8979(99)02518-9].