New optical disk system of ultra high density and high data rate using 2D VCSEL array: nanofabrication for evanescent light enhancement by surface plasmon polariton

Higher density optical disk system of super parallel optical heads using a two dimensional VCSEL array are described for the higher data transfer rate and technological capability. Optical heads of the VCSEL array and microlens array play a key role to get higher evanescent light from a small aperture for the optical disk system, of which disk surface is coated with a lubricant and protective film on the flat recording medium in order to keep the gap between the super-parallel optical head and the disk surface within 20 nm. Higher throughput efficiency has been obtained in the near-field semiconductor optical probe array head. However, the obtained evanescent light power is about 10μW from the 100nm probe aperture using a VCSEL 1mW laser output power, which is still not enough to write bits on the phase change optical disk medium. One solution for improvement of the writing power is to develop a special nano-fabricated corrugated thin metal film for higher throughput efficiency by surface plasmon polariton enhancement. A metal fine grating fabrication method to get evanescent light wave resonantly enhancement has been studied with a FDTD simulation result.