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. 

Fig. 2.12 Basic concept of functional hierarchy of hierarchical hologram. In principle, no interference occurs between the two layers, the far-mode and the near-mode...

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. 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., Nomura, W., Yatsui, T., Naruse, M., Ohtsu, M. (2008). Hierarchical hologram based on optical near- and far-field responses. Optics Express, Vol. 16, pp. 607-612, 2008... 

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