Improved performance in coaxial holographic data recording

Abstract

We describe a coaxial holographic recording system for achieving high recording density. We implement several techniques, such as an objective lens with high numerical aperture (NA), high capacity page data format, a random binary phase mask, and an optical noise reduction element. Our system successfully realizes a hologram recording/retrieving at a low diffraction efficiency less than 2.0 x 10(-3) and achieves a raw data density of 180 Gbit/in.(2), thus demonstrating the potential of a coaxial holographic system for high-density optical storage systems.

Diffraction Property of Collinear Holographic Storage System

“…( [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19], it shows that the PSF is related to the auto-correlation function of the reference pattern times a defocusing phase term. Accordingly, a lens array used as the reference is introduced.…”

“…Even so, 80% of energy is wasted due to the opaque part in the reference region. The random binary phase (RBP) modulation is proposed to solve this problem, which is shown to improve the PSF without wasting energy in reference modulation [16,17]. In this section, a novel technique called lens array phase (LAP) modulation is further proposed to improve the PSF..…”

Interpixel crosstalk cancellation on holographic memory

“…Furthermore, this technique is not limited to an angle multiplexing system and can be applied to any architecture that employs page data, for example, a coaxial system. 20,21) …”

Intermediate Holographic Data Storage System by Using Sequentially Superimposed Recording

“…In recent studies of the holographic storage system, the co-axial lens system has been one of the main issues [9][10][11][12][13]. This lens system is simple and makes it easy to perform the angular multiplexing.…”