Error Rate Improvement of 75 nm Super-RENS Signal in 405nm, 0.85 NA System

We report the error rate improvement of super-resolution near field structure (Super-RENS) write-once read-many (WORM) disk at a blue laser optical system. (Laser wavelength 405 nm, numerical aperture 0.85) We used a disk of which carrier level of 75 nm is improved. We controlled the equalization (EQ) characteristics and used the adaptive write strategy and advanced partial-response maximum likelihood (PRML) technique. We obtained bit error rate (BER) of 10-4 level with new signal processing techniques. This result shows high feasibility of super-RENS technology for practical use