Effects of symbol modulation coding on readout fidelity of shift-multiplexed holographic digital data page storage in a photopolymerizable nanoparticle-(thiol-ene)polymer composite film

Abstract

We report on shift-multiplexed holographic storage of 250 digital data pages in a photopolymerizable SiO₂ nanoparticle-polymer composite film being capable of step-growth thiol-ene polymerization in the green. Various two-dimensional symbol modulation codes for the digital data page format were employed to examine the dependence of the readout fidelity on modulation coding schemes. It is found that, as compared to 1:2 and 2:4 modulation codes, higher-order 5:9, 9:16, and 13:25 modulation codes possessing reduced white rates and higher coding efficiencies give lower symbol-error rates of ~1×10⁻³ and higher signal-to-noise ratios (>4).

Photopolymerizable nanocomposite photonic materials and their holographic applications in light and neutron optics

“…To further mitigate polymerization shrinkage occurring in NPC films during recording, Hata et al [ 73 – 75 ], and Mitsube et al [ 76 ] proposed the use of TE and TY photopolymerizations that proceed via a step growth radical addition mechanism for volume holographic recording in NPCs. Using such a new NPC system, Momose et al demonstrated holographic shift multiplexing of more than one hundred 2D digital data pages with high fidelity readout [ 78 , 79 ]. This demonstration will be described in Section 4.1 .…”

“…As described in Section 3.1.2 , volume gratings recorded in the TE-based NPC incorporating inorganic nanoparticles satisfy these requirements [ 73 , 74 ], suggesting their use for HDS media. Indeed, it was shown that TE-based NPCs gave good performance in shift-multiplexed holographic digital data page storage [ 78 , 79 ].…”

“… SNRs of reconstructed holograms as a function of data page number for 1:2, 2:4, and 5:9 symbol modulation coding formats (above) and for 9:16, 10:16, and 13:25 symbol modulation coding formats (below) [ 79 ]. The horizontal dotted lines are a guide to the eye.…”

“…Moreover, one can even utilize the nucleus–neutron interaction (strong force) between holographically assembled nanoparticles in NPCs and incident neutrons to manipulate neutron beams by neutron diffraction from holographic gratings recorded in NPCs. These photonic and neutron optics applications include HDS [ 78 , 79 ], security holograms [ 52 ], holographic sensors [ 80 ], nonlinear optics [ 81 ], distributed feedback lasers [ 82 , 83 ], and holographic control of slow-neutron beams [ 84 – 87 ].…”

Characterization of volume holographic recording in photopolymerizable nanoparticle-(thiol-ene) polymer composites at 404 nm

“…31 Using such thiol-ene based NPCs at the stoichiometric thiol-to-ene ratio, we showed shrinkage reduction below 0.5% with Dn sat as large as 1 Â 10 À2 and S higher than a) Electronic mail: ytomita@uec.ac.jp 0021-8979/2015/117(5)/053105/6/$30.00 V C 2015 AIP Publishing LLC 117, 053105-1 Furthermore, we used such thiol-ene based NPCs as greensensitized HDS media to demonstrate the excellent performance in holographic shift multiplexing of more than 200 of 2D digital data pages with high fidelity. 32,33 The thiol-ene photopolymerization mechanism was also used to record electrically switchable reflection gratings in holographic polymer-dispersed liquid crystals at Ar-ion and solid-state laser lines of 364, 442, 488, and 532 nm. 31,[34][35][36] Thanks to the recent development of highly coherent blue diode lasers for HDS, 37 it is possible to implement compact HDS systems in the blue (at and near the 405-nm diode laser line).…”