Efficient Achromatic Broadband Focusing and Polarization Manipulation of a Novel Designed Multifunctional Metasurface Zone Plate

Abstract

In this paper, comprehensively utilizing the diffraction theory and electromagnetic resonance effect is creatively employed to design a multifunctional metasurface zone plate (MMZP) and achieve the control of polarization states, while maintaining a broadband achromatic converging property in a near-IR region. The MMZP consists of several rings with fixed width and varying heights; each ring has a number of nanofins (usually called meta-atoms). The numerical simulation method is used to analyze the intensity distribution and polarization state of the emergent light, and the results show that the designed MMZP can realize the polarization manipulation while keeping the broadband in focus. For a specific design wavelength (0.7 μm), the incident light can be converted from left circularly polarized light to right circularly polarized light after passing through the MMZP, and the focusing efficiency reaches above 35%, which is more than twice as much as reported in the literature. Moreover, the achromatic broadband focusing property of the MMZP is independent with the polarization state of the incident light. This approach broadens degrees of freedom in micro-nano optical design, and is expected to find applications in multifunctional focusing devices and polarization imaging.

Metasurfaces toward Optical Manipulation Technologies for Quantum Precision Measurement

“…Propagation phasetype metasurfaces tend to keep the structure thickness constant and change the phase by adjusting the equivalent refractive index or the propagation constant. The equivalent refractive index theory is usually composed of periodic arrays of high-refractiveindex nanopillars and low-refractive index dielectric bases, and the equivalent refractive index is achieved by controlling the duty cycle of the structural unit as a way to control the phase of electromagnetic waves, for example, the change in equivalent refractive index is usually achieved by changing the diameter [110,111] and height [112] of the high-refractive index dielectric material. Different from the equivalent refractive index theory, the surface plasmon waveguide theory uses the property that the propagation constant varies with the width of the slit in the surface plasmon waveguide to regulate the refractive index and the local phase, [113][114][115] as shown in Figure 4a.…”

Editorial for Special Issue “Plasmon Assisted Near-Field Manipulation and Photocatalysis”

“…A silicon square-hole nanodisk array device was proposed in order to realize multi-Fano resonances with a high Q-factor, narrow line width, large modulation depth and enhanced near-field enhancement, which could provide the basis for the application of a novel method in the realms of multi-wavelength communications, lasing, and nonlinear optical devices [5]. Then, a nested composite structured multifunctional metasurface zone plate was designed and fabricated by integrating the metasurface onto the surface of the multi-level diffraction lens rings [6]. Based on the global optimization mathematical iterative method, the height distribution of the multifunctional metasurface zone plate was optimized in order to realize an extremely efficient achromatic broadband focus.…”