Digital holographic storage system incorporating thermal fixing in lithium niobate

Abstract

We describe a digital holographic data storage system that uses in situ thermal fixing to achieve nonvolatile readout. The system was used to store and fix 530 holograms representing 1.7 MB of digital data. The system demonstrates that fixing by heating after recording gives adequate performance for multiplex holography in the perpendicular recording geometry. The postrecording heating procedure is preferred over high-temperature recording in the perpendicular geometry to achieve Bragg matching for the entire signal angular bandwidth.

Non-volatile holographic storage in doubly doped lithium niobate crystals

“…Like C 60 and C 70 , C 74 possesses only one possible isolated pentagon structure. Previous low-level Hückel molecular orbital 1,11 and tight-binding molecular dynamics calculations 7,12 on C 74 (D 3 ) predicted a small bandgap, and it has been suggested that this could explain its insolubility 7 . More accurate density functional theory calculations (Fig.…”

“…But there remains a problem with volatility: the read-out process usually erases the stored information and amplifies the scattered light. Several techniques for 'fixing' holograms have been developed [3][4][5][6] , but they have practical disadvantages and only laboratory demonstrators have been built [7][8][9][10] . Here we describe a resolution to the problem of volatility that should lead to the realization of a more practical system.…”

“…Recording with light of one wavelength and just reading with light of a longer one causes substantial information losses due to the Bragg condition of volume diffraction 6 . Even though all these techniques work [7][8][9][10] , the outlined disadvantages have made holographic data storage impractical thus far.…”

“…Solvation allows extraction of fullerene clusters from carbon soot 3 , isolation of individual structures, and derivatization to form new compounds. Isomers of C 60 through to C 96 have been isolated and identified [4][5][6] , and these extractable isomers share common electronic features 7 . Specifically, both experimental [8][9][10] and computational 11,12 investigations show that all soluble fullerenes have large bandgaps.…”

Implementation of single-beam multiplexing encoding with a dually modulated spatial light modulator

“…The storage capacity of multiplexing encoding does not only depend on the property of recording medium, like volume recording medium Fe:LiNbO 3 , but is also limited by the optical setup. The volume medium has been researched a lot [22,23]. In this paper, we only want to analyze the effect of the single-beam optical setup on the storing capacity with a two-dimensional recording medium.…”