Morihisa Hoga

  • Citations Per Year
Learn More
A hierarchical hologram works in both optical far-fields and near-fields, the former being associated with conventional holographic images, and the latter being associated with the optical intensity distribution based on a nanometric structure that is accessible only via optical near-fields. We propose embedding a nanophotonic code, which is retrievable via(More)
We experimentally demonstrated the basic concept of modulatable optical near-field interactions by utilizing energy transfer between closely positioned resonant CdSe/ZnS quantum dot (QD) pairs dispersed on a flexible substrate. Modulation by physical flexion of the substrate changes the distances between quantum dots to control the magnitude of the coupling(More)
Artifact metrics is an information security technology that uses the intrinsic characteristics of a physical object for authentication and clone resistance. Here, we demonstrate nano-artifact metrics based on silicon nanostructures formed via an array of resist pillars that randomly collapse when exposed to electron-beam lithography. The proposed technique(More)
Recently, Italy’s National Committee for Cultural Heritage found some microscopic codes in Mona Lisa’s pupils by using a magnifying glass (Lorenzi, 2010). Experts have pointed out that the codes may represent several messages, including the initials of Leonardo Da Vinci, "LV". On the other hand, how and why such microscopic messages were embedded in her(More)
We demonstrate that a two-layer shape-engineered nanostructure exhibits asymmetric polarization conversion efficiency thanks to near-field interactions. We present a rigorous theoretical foundation based on an angular-spectrum representation of optical near-fields that takes account of the geometrical features of the proposed device architecture and gives(More)
Nano-artifact metrics exploit unique physical attributes of nanostructured matter for authentication and clone resistance, which is vitally important in the age of Internet-of-Things where securing identities is critical. However, expensive and huge experimental apparatuses, such as scanning electron microscopy, have been required in the former studies.(More)
Optical near-field interactions exhibit high-efficiency energy transfer between closely positioned nanometric materials, and the subsequent optical response induced by the transfer can be controlled by modulating the spatial distribution. We experimentally demonstrated the basic concept of such modulatable optical near-field interactions, termed Modulatable(More)
  • 1