Search

In this paper, we propose a simple model, a combination of effective medium theory and the Jones matrix, to analyze the optical properties of a dielectric PB-phase metasurface with an arbitrary incident polarization state. The optical properties, such as the polarization conversion efficiency spectrum, rotation-angle-dependent phase modulation, and phasor diagram, shows a fair agreement with the finite difference time domain method results. This model provides a fast and sufficient accuracy compared to the time-consuming finite element methods. Moreover, the shortness of the proposed model is also discussed.

This study presents the design and fabrication of a dielectric metasurface with free-form phase distribution and with a large period unit cell. The dielectric metasurface is fabricated using i-line stepper, dry etching, and nanoimprint technology. The phase distribution of the meta-device is the combination of a blazed grating for deflection and an aspherical lens for eliminating the off-axis aberration. The optical measurement result shows the off-axis focusing spot is with loss aberration and the corresponding Strehl ratio is 0.34. The diffraction efficiency is around 2%. The low efficiency is mainly attributed to the rounding of the rectangular nanostructures during the pattern transfer and relatively thin thickness. Moreover, the polarization-dependency of this large period metasurface is also discussed.