Distance control in optical near-field recording/reproducing apparatus

摘要

The invention concerns a recording apparatus for reproducing information recorded on a recording medium by utilising near-field light. The recording apparatus comprises: an aperture element having a microscopic aperture to scatter near-field light; a light illuminating means for introducing illumination light to the recording medium such that near-field light is created on a surface of the recording medium, the illumination light comprising two different modulation frequencies; a first light detecting means for detecting first propagation light caused by the microscopic aperture scattering the near-field light having one of the two modulation frequencies, and for converting the detected first propagation light into a reproduced signal; a second light detecting means for detecting second propagation light caused by the microscopic aperture scattering the near-field light having the other of the two modulation frequencies, and for converting the detected second propagation light into a control signal; and a control means for controlling a spacing between the aperture element and the recording medium based on the control signal.