The media heating device of the magnetic head includes an optical resonant cavity and a nano-pin that produces a high intensity near-field optical beam of sub-wavelength dimension adjacent to the write pole. The cavity is fabricated as a planar thin film structure in layers that are generally parallel to the magnetic pole thin film layers of the magnetic head, such that a principal axis of the resonant cavity is parallel to the air bearing surface (ABS). Optical energy is coupled into the resonant cavity through a waveguide that is placed proximate the cavity, and optical energy is coupled out of the cavity through a nano-pin that is disposed between the resonant cavity and the ABS.