Ultrahigh-capacity non-periodic photon sieves operating in visible light.

Kun Huang,Jinghua Teng,Hong Liu,Francisco J Garcia-Vidal,Minghui Hong,Boris Luk’Yanchuk,Cheng-Wei Qiu

doi:10.1038/ncomms8059

Abstract

Miniaturization of optical structures makes it possible to control light at the nanoscale, but on the other hand it imposes a challenge of accurately handling numerous unit elements in a miniaturized device with aperiodic and random arrangements. Here, we report both the new analytical model and experimental demonstration of the photon sieves with ultrahigh-capacity of subwavelength holes (over 34 thousands) arranged in two different structural orders of randomness and aperiodicity. The random photon sieve produces a uniform optical hologram with high diffraction efficiency and free from twin images that are usually seen in conventional holography, while the aperiodic photon sieve manifests sub-diffraction-limit focusing in air. A hybrid approach is developed to make the design of random and aperiodic photon sieve viable for high-accuracy control of the amplitude, phase and polarization of visible light. The polarization independence of the photon sieve will also greatly benefit its applications in optical imaging and spectroscopy.

Highlights

Miniaturization of optical structures makes it possible to control light at the nanoscale, but on the other hand it imposes a challenge of accurately handling numerous unit elements in a miniaturized device with aperiodic and random arrangements
We report a random photon sieve composed of 34,034 subwavelength holes, demonstrating an optical hologram with a diffraction efficiency of 47%, as well as high uniformity along with polarization independence
We propose a twofold method: (1) a hybrid approach combining the coupled-mode theory[3,22] and multipole expansion method[23,24] is proposed to accurately model the optical field diffracted from one single subwavelength hole, as shown in Fig. 1a, which is formulated by the superimposing elementary mathematical functions (see equation (3) in the Methods section); (2) the far-field diffracted field of the entire photon sieve sketched in Fig. 1b is obtained by coherently superimposing optical fields diffracted from each subwavelength hole (see equation (4))

Summary

Introduction

Miniaturization of optical structures makes it possible to control light at the nanoscale, but on the other hand it imposes a challenge of accurately handling numerous unit elements in a miniaturized device with aperiodic and random arrangements. This method only worked well in paraxial optics for conceptual demonstration of optical holography[12,13] and optical focusing without breaking the diffraction limit[14,15,16,17] To overcome these challenges, we propose a hybrid approach that strategically combines the coupled-mode theory and the multipole expansion method to describe the diffracted field from a huge number of subwavelength holes with high accuracy. We propose a hybrid approach that strategically combines the coupled-mode theory and the multipole expansion method to describe the diffracted field from a huge number of subwavelength holes with high accuracy It gains physical insight into the diffraction issue in terms of elementary mathematical functions, and it makes the optimization algorithms feasible in the structural design of a photon sieve aiming for high-quality holograms and superfocusing. This work offers a viable method to tackle ultrahigh-capacity random or aperiodic subwavelength features to accurately tailor the functionalities of optical devices via manipulating phase, amplitude and polarization of light beyond the evanescent region

Methods

Results

Conclusion