High density substrate incident magneto-optic recording using a solid immersion lens

A system demonstrating ultra-high optical recording densities is presented. A substrate incident solid immersion lens was implemented and integrated into a blue wavelength optical spin stand. The spin stand was designed to work without a focus or tracking servo. The optical readout spot size was determined to be approximately 250 nm from the impulse response of the system and was also verified by swept sine wave methods. The system signal-to-noise characteristics were determined by integration of the Fourier decomposition of the readout signal and by autocorrelation techniques. The signal to noise ratio for low frequency data was 23 dB. Finally, domains as small as 80 nm were recorded and readout using this system and the associated signal to noise ratio was shown to be approximately 10 dB.