The influence of various types of aberrations of recording and readout beams on the signal-to-noise ratio of the readout signal in microholographic recording was investigated through a numerical simulation. The simulation conditions were that the wavelength of the laser was 405 nm and the numerical aperture of the objective lenses was 0.85. The tolerance of the root-mean-square (RMS) wavefront aberrations was defined as the aberration when the signal-to-noise ratio with aberrations was comparable to that without aberrations. When both the recording and readout beams were aberrated and the signs of the aberrations were in the worst case, the tolerance of the RMS wavefront aberrations was 0.035λ regardless of the types of aberrations, which was half of the Maréchal’s criterion. Moreover, when the RMS wavefront aberrations of the recording and readout beams were within the above value and the signal-to-noise ratio of 2 was allowed, the bit intervals of 0.15 and 0.75 μm in the in-plane and vertical directions, respectively, which correspond to the recording density of 59 bit/μm³ (recording capacity of 10 TB), were shown to be feasible for confocal detection.

Date Published: 5 September 2014
PDF: 6 pages
Proc. SPIE 9201, Optical Data Storage 2014, 92010I (5 September 2014); doi: 10.1117/12.2062408

Published in SPIE Proceedings Vol. 9201:
Optical Data Storage 2014
Ryuichi Katayama; Thomas D. Milster, Editor(s)