Multiple storage and erasure of fixed holograms in Fe−doped LiNbO3

Abstract

Holograms were recorded and fixed simultaneously in heated (∼160°C) crystals of Fe−doped LiNbO3. With this procedure the crystals have the erase/write asymmetry required for multiple storage of high−diffraction−efficiency holograms. Five hundred fixed holograms, each with more than 2.5% diffraction efficiency, were recorded.

Holographic Data Storage Systems

“…Optical damage and crosstalk limitations are not considered. In practice, however, optical damage often tends to limit capacity, but can be significantly reduced by recording at elevated temperatures [68] or by using periodically poled media. Equation (52) provides an upper bound.…”

“…In the second approach, both electronic and ionic gratings are formed simultaneously at an elevated temperature [68]. Simultaneous formation of electronic and ionic gratings typically results in stronger complementary gratings because of mutual screening during formation, in which the magnitudes of both gratings may be substantial, but their difference remains relatively small [69], [70].…”

“…In lithium niobate, for example, subsystem may establish an initial electronic charge density through the photorefractive effect, and subsystem is established as a complementary charge density through mobile ion transport at elevated temperature [68]- [71] (Fig. 36).…”

“…[68], [74]- [76]. At least 500 holograms may be stored using ionic gratings and for which diffraction efficiencies in the range of 2-25% have been reported [68], [75], [76].…”

Optical network for real-time face recognition

“…The holograms will decay when exposed to light during the testing phase. We can overcome this decay by either thermally fixing the hologram 23 or by using dynamic copying. [10][11][12] In this experiment we adopted a simpler route that temporary overcomes this problem.…”