Patent attributes
A very small spot-size light beam forming apparatus of the present invention comprises: a conductive film for generating a surface plasmon when an inputted light is applied thereto: a plurality of nano projections, each connected to the conductive film at one end, for receiving a portion of the surface plasmon, and outputting a plurality of input surface plasmons, respectively, from the other end of each of the plurality of nano projections, the other end of each of the plurality of nano projections having a diameter smaller than a wavelength of the inputted light; a coupling unit, connected to the other end of each of the plurality of nano projections, for receiving and coupling the plurality of input surface plasmons, so as to generate a coupled surface plasmon; and a negative-refractive-index lens, connected to the coupling unit and having a negative refractive index, for receiving a near-field light generated due to the coupled surface plasmon, and collecting the near-field light on a recording surface of the optical information storage disk, and a near-field light obtained through collection on the recording surface has a diameter smaller the wavelength of the inputted light.