Magnetic recording disk drive with shingled writing and wide-area thermal assistance

A thermally-assisted recording (TAR) disk drive uses a "wide-area" heater with "shingled" recording. In shingled recording, the write head pole tip is wider than the read head in the cross-track direction and writes magnetic transitions by making a plurality of consecutive circular paths that partially overlap. The non-overlapped portions of adjacent paths form the data tracks, which are thus narrower than the width of the write pole tip. The data tracks are grouped into annular bands and when data is to be rewritten, all of the data tracks in an annular band are also rewritten. The wide-area heater may be a waveguide with an output end that generates a heated area on the disk recording layer which is wider than the cross-track width of the write pole tip. It has been determined that the use of a wide-area heater with shingled recording does not result in any significant adjacent track erasure (ATE).