All-metal flexible large-area multiband waveplate

Abstract

We propose and demonstrate an all-metal flexible reflective multiband waveplate based on nano-grating structure using high efficient electroplating growing process, which exhibits quarter waveplate at two wavelengths (λ = 465nm and λ = 921nm) and half waveplate at another wavelength (λ = 656nm). Using Finite Difference Time Domain (FDTD) modeling, the phase shift and reflection efficiency are simulated and designed for a variety of geometrical parameters. A fast and cost-effective technique based on conventional interference lithography and nickel electroplating process is demonstrated to fabricate the all-metal, large-area and flexible waveplate. Experimental results show that the fabricated monolithic all-metal nano structure of the proposed device are in high fidelity with the structure on template and the optical performance of the device are in excellent agreement with the theoretical prediction. The proposed structure and the fabrication method suggests an effective way to realize all-metal, ultrathin, self-supporting and flexible devices for various applications in rugged environment such as high temperature or high pressure environment, and also in the fast growing fields of flexible (wearable) optoelectronics, flexible displays and other curved or nonplanar devices.

High-Efficiency and Wide-Angle Versatile Polarization Controller Based on Metagratings

“…Due to the dispersion, β may achieve ±π/2 and ±π at different wavelengths, thereby a single device can exhibit multifunctional polarization conversion as both quarter-wave and half-wave plates [40,41]. However, such multifunctional wave plates are only able to operate within a narrow band due to the dispersion nature.…”

“…In this work, we choose the grating structure to achieve multiple polarization conversion because of its simultaneous control of phases and amplitudes capabilities [40,41,42,45]. Benefiting from the concept of metamaterials, we are able to control α , β , and even operating modes through a more flexible approach by integrating artificial meta-atoms into conventional gratings.…”

“…Recently, considerable efforts have been devoted to integrating multiple functionalities into a single meta-device [31,33,34,35,36], and some multifunctional polarization controllers, such as multi-modal reflective metasurface polarization generator [37], metasurface with absorption and polarization conversion functions [38], metasurface with reconfigurable conversions of reflection, transmission, and polarization states [39], have been demonstrated. Additionally, some previous papers have concluded that grating structures can also realize multiple polarization conversions [40,41,42]. In spite of the described advantages, some of these polarization controllers need to integrate multifarious complex supercells to accomplish multi-functionalities [37], which are unfavorable to the structure design and fabrication process.…”

“…In spite of the described advantages, some of these polarization controllers need to integrate multifarious complex supercells to accomplish multi-functionalities [37], which are unfavorable to the structure design and fabrication process. Additionally, limited by the current design concept, these multifunctional polarization controllers work in single reflective or transmissive mode merely [37,38,39,40,41,42], and to date, a multifunctional polarization controller that can operate in dual modes, which may find important applications in multipath systems, has not yet been obtained. Thus, efficiently integrating multiple distinct polarization conversion functions and dual operating modes into a single polarization controller composed of simple geometric structures is meaningful and still a challenge.…”

Optical wave retarder based on metal-nanostripe metamaterial

“…Hence, alternative principles of optical wave retardation by nanostructures are of great interest. Previously, also nanopatterned metal surfaces have been demonstrated to provide wave retardation for reflected light [14][15][16][17]. However, they cannot be used in the usually more convenient transmission mode.…”