The Dynamic Readout performance of a micro-optical head, consisting of a semiconductor laser on a flying slider and a glass substrate disk medium has been examined. An antireflection coated (ARC) laser diode, whose reflectivity facing a medium, is less than 5%, is useful in decreasing signal amplitude fluctuation due to the head-to-medium spacing.

Some sampled servo signal characteristics of an optically switched laser diode (OSL) head are examined. Wobbling signal amplitude increases with bias current and is proportional to the light beam deviation from a track center at around the threshold current corresponding to the low reflection part of the medium. It is confirmed that OSL head tracking can be realized using the sampled servo method.