Polarization controlled colorful images reconstructed by reflective meta-hologram

• Main Authors: Huang, Yao-Wei, Chen, Wei Ting, Yang, Kuang-Yu, Wang, Chih-Ming, Wu, Pin Chieh, Sun, Greg, Sun, Shulin, Zhou, Lei, Liu, Ai Qun, Tsai, Din Ping
• Other Authors: Engheta, Nader
• Format: Conference or Workshop Item
• Language: English
• Published: 2015
• Subjects: DRNTU::Engineering::Electrical and electronic engineering::Antennas, wave guides, microwaves, radar, radio
• Online Access: https://hdl.handle.net/10356/106728; http://hdl.handle.net/10220/25097; http://dx.doi.org/10.1117/12.2063297
• Institution: Nanyang Technological University

Holograms, the optical devices to reconstruct pre-designed images, have been evolved dramatically since the advances in today’s nanotechnology [1-4]. Metamaterials, the sub-wavelength artificial structures with tailored refraction index, enable us to design the meta-hologram working in arbitrary frequency region. Here we demonstrated the first reflective type, dual image and high efficient meta-hologram with the incident angle as well as the coherence of incident wave insensitivity in visible region at least from λ = 632.8 nm to λ = 850 nm. The meta-hologram is composed of 50-nm-thick gold cross nano-antenna coupled with 130-nm-thick gold mirror with a 50-nm-thick MgF2 as spacer. It shows different images “RCAS” and “NTU” with high image contract under x- and y-polarized illumination, respectively. Making use of the characteristic of meta-materials, these optical properties of proposed meta-hologram can be transferred to arbitrary electromagnetic region by scale-up the size of the unit cell of meta-hologram, leading to more compact, efficient and promising electromagnetic components.