Nanometric holograms based on a topological insulator material

Abstract

Holography has extremely extensive applications in conventional optical instruments spanning optical microscopy and imaging, three-dimensional displays and metrology. To integrate holography with modern low-dimensional electronic devices, holograms need to be thinned to a nanometric scale. However, to keep a pronounced phase shift modulation, the thickness of holograms has been generally limited to the optical wavelength scale, which hinders their integration with ultrathin electronic devices. Here, we break this limit and achieve 60 nm holograms using a topological insulator material. We discover that nanometric topological insulator thin films act as an intrinsic optical resonant cavity due to the unequal refractive indices in their metallic surfaces and bulk. The resonant cavity leads to enhancement of phase shifts and thus the holographic imaging. Our work paves a way towards integrating holography with flat electronic devices for optical imaging, data storage and information security.

A fibre-coupled UHV-compatible variable angle reflection-absorption UV/visible spectrometer

“…Using this mean value, thicknesses as both a function of dose at a fixed angle and as a function of angle at a fixed dose can be determined using equation (5). Error values are calculated using the upper and lower values of n. Figure 6 shows the determined thicknesses of doses from 100 Lm -1000 Lm at the narrowest reflection angle of 31°.…”

“…4 Recently it has been demonstrated that a detailed knowledge of the refractive index of a material is important in the design of holographic devices. 5 In contrast to inorganic materials, organic materials are relatively poorly studied. 6 Optical properties of ices are of particular interest to the astrochemical community.…”

Observation of Type I Photonic Weyl Points in Optical Frequencies

“…The cladding is realised by the atomic layer deposition (ALD) of ∼110 nm of antimony telluride (Sb 2 Te 3 ) thin films . This material is chosen because of its high refractive index of 5 and good transparency at mid‐IR wavelengths (for experimental details, see Experimental section, Supporting Information Figures S5 and S6).…”

“…The growth rate was 0.01 nm per cycle. The X‐ray diffraction (XRD) and Raman spectrum reveal the high quality of the ALD grown Sb 2 Te 3 thin film …”

Ultrathin Planar Cavity Metasurfaces

“…Recently, strong interference effect in highly absorptive media is proposed for realizing wide‐angle spectral selective absorbers and light harvesting devices . These studies show that the strong nanocavity interference occurs within a stack of layers composed of ultrathin lossy materials and metallic substrates.…”