Various systems and methods are provided to achieve laser power control. By recording additional information for data reproduction in each sector on a data reproducing medium as a subcode separately from data when the data is recorded in the unit of sector, reproduction of data can be controlled using the subcode, thus making it possible to remarkably improve the availability of the data recording medium. The lower electrode and the upper electrode are electrically connected via an opening provided on the second inter-electrode insulating film. The location of the meeting place is also determined.