High Density Magneto-optical Recording With A SHG Green Laser

Recording with a light source of shorter wavelength and a high NA objective lens is essential to realize optical data storage at high areal density. Laser-diode pumped Nd:YAG SHG green lasers offer this potential. We have developed a high power green laser and a low noise GdFeCo/lbFeCo MO disk for the wavelength of 532 nm. With a newly designed optical pick-up and an objective lens of 0.6 NA, a C/N ratio > 48 dB was obtained for mark length ?f 0.45 μm.