Analytical solution for side-fringing fields in perpendicular recording

Through the use of conical coordinates and in the limit of small pole lenght, flying height, and medium thickness, the three-dimensional field from a beveled probe-type recording head with a permeable magnetic underlayer has been determined in a simple closed form. For a given bevel angle the spectral response to perpendicularly magnetized media off the side of the head depends on one dimensionless parameter. The field solution is used to find the quasi-exponential falloff of this response as a function of the bevel angle. For a large bevel angle this recording geometry is shown to be less sensitive to side pickup than a conventional gapped recording head.