Super-Resolution Near-Field Blue Laser Type Optical Disk with Modified Coumarin Dye Recording Layer and Poly(methyl methacrylate) Contrast Enhanced Layer

A new coumarin derivative with blue light absorption was designed and synthesized. The absorption properties and thermal stability of the coumarin derivative were discussed. We also studied the characteristics of a super-resolution near-field blue laser type optical disk with a modified coumarin recording layer and a poly(methyl methacrylate) (PMMA) contrast enhanced layer. A sample disk, which consists of a spin-coated coumarin derivative recording layer and a PMMA contrast enhanced layer, showed excellent recording and readout characteristics with a carrier-to-noise ratio (CNR) of about 33 dB for a mark length of 100 nm (laser wavelength = 405 nm, numerical aperture = 0.65). These results indicate that the coumarin derivative dye is a promising candidate for optical recording by a super-resolution near-field structure (super-RENS) technique.