Recently, we found that a specially designed optical disk has the potential to amplify optical signals by surface plasmons generated over recorded marks. Since 1997, we have focused our research on super-density optical data storage specially using near-field optics and developed the novel disk structure named "super-resolution near-field structure (super-RENS)." Super-RENS was originally designed to enhance the signals of marks recorded in less than the diffraction limit. However, introducing and crossing two laser beams at one focused spot, one of the beams passing through the disk was amplified by adjusting another laser beam power. The amplifier was operated in a thin and small area in less than 100 nm and 1.0 µm.