Polarisation interferometry flying height testing

The in-depth analyses of polarisation interferometry flying height testing are presented. The drawbacks of the oblique incidence polarisation interferometry method are discussed. The application of the dual-beam normal incidence polarisation interferometry method is illustrated. It is shown that with this normal incidence polarisation interferometer, not only the flying height can be measured down to contact without losing accuracy, but the optical parameters of the head-slider can also be determined.