Nanophotonic Hierarchical Hologram

A nanophotonic hierarchical hologram can be created by adding a nanometric structural change to a conventional embossed hologram. Figure 2.12 shows the basic composition of the hierarchical hologram. 

Nanophotonic Hierarchical Holograms Demonstration of Hierarchical Applications... 

We can see the hierarchy of optical near-fields and far-fields because optical near-field interactions are distinguishable with propagating light. This characteristic feature has led to hierarchical optical system designs, such as nanophotonic hierarchical holograms (Tate et al., 2008), where independent functions are associated with both optical near- and far-fields in the same device. Figure 3 shows the basic concept of the hierarchical hologram. 

Fig. 3. Basic concept of functional hierarchy of nanophotonic hierarchical hologram. In principle, no interference occurs between each layer, because optical near-field interachons are dishnguishable from the convenhonal hologram view, which consists of diffracted propagating light.

Fig. 5. Schematic diagram of the sample device for demonstration of nanophotonic hierarchical hologram with a nanophotonic code embedded within the embossed structure of Virtuagram .

In this chapter, we described the basic concept of a nanophotonic hierarchical hologram and a nanophotonic code embedded in a hologram as an implementation of a hierarchical hologram. One of the most notable characteristics of our proposed approach is embedding a nanophotonic code within the patterns of a hologram composed of one-dimensional grid structures it yields clear polarization dependence compared with an isolated nanophotonic code that is not embedded within a grid structure. These features were successfully demonstrated both numerically and experimentally. 

Tate, N., Naruse, M., Yatsui, T., Kawazoe, T., Hoga, M., Ohyagi, Y., Fukuyama, T., Kitamura, M., Ohtsu, M. (2010). Nanophotonic code embedded in embossed hologram for hierarchical information retrieval. Optics Express, Vol. 18, pp. 7497-7505, 2010... 

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