0.04 \mbiμm Domain Expansion Readout for the Magnetic Amplifiying Magneto Optical System
Abstract
Read/write characteristics of the magnetic amplifying magneto optical system (MAMMOS) with alternative readout fields such as carrier to noise ratio (C/N), eye pattern, jitter and bit error rate (BER), are investigated with a 640 nm wavelength laser diode and 0.55 numerical aperture of the objective lens. The C/N value of 0.12 μm is 50 dB and is independent of the mark length. A very clear eye pattern was observed. The results show that the jitter value is less than 3% compared with the window width and it is only dependent on the switching speed of the readout field. The error rate is improved by using a thin recording layer of 50 nm in thickness. The minimum domain length which yields a BER of less than 1× 10-4 is 0.045 μm (45 nm); the minimum space length is 0.10 μm (100 nm). These results are confirmed at a track pitch of about 0.40 μm. By using a digital versatile disk (DVD) pickup, the areal density can be estimated to be about 23 Gbit/in2 with the user data capacity of 30 GB/120 mmφ. By using a 400 nm blue laser diode, these values are estimated as 59 Gbit/in2 and 77 GB/120 mmφ.
- Publication:
-
Japanese Journal of Applied Physics
- Pub Date:
- February 2000
- DOI:
- 10.1143/JJAP.39.725
- Bibcode:
- 2000JaJAP..39..725A