We report certain diffraction effects that are pertinent to the operation of double-layer optical recording media. The diffraction of light from the out-of-focus layer and the resulting distribution on the in-focus layer are studied using computer simulations. The findings are then verified by direct measurements. We also describe a technique for analyzing (by computer simulation) the focus-error signa, FES, in systems that use the astigmatic method in conjunction with the double-layer disk. The results of our computer simulations of the FES are compared with those measured in an actual disk drive; good agreement between computation and measurement is obtained.

Date Published: 30 July 1997
PDF: 9 pages
Proc. SPIE 3109, Optical Data Storage 1997 Topical Meeting, (30 July 1997); doi: 10.1117/12.280687

Published in SPIE Proceedings Vol. 3109:
Optical Data Storage 1997 Topical Meeting
Henryk Birecki; James Z. Kwiecien, Editor(s)