Metalens-integrated compact imaging devices for wide-field microscopy

Chen Chen,Cheng Yang,Beibei Xu,Tao Li,Shenglun Gao,Hanmeng Li,Shining Zhu,Xia Hua,Feng Yan

doi:10.1117/1.ap.2.6.066004

Abstract

Metasurfaces have demonstrated unprecedented capabilities in manipulating light with ultrathin and flat architectures. Although great progress has been made in the metasurface designs and function demonstrations, most metalenses still only work as a substitution of conventional lenses in optical settings, whose integration advantage is rarely manifested. We propose a highly integrated imaging device with silicon metalenses directly mounted on a complementary metal oxide semiconductor image sensor, whose working distance is in hundreds of micrometers. The imaging performances including resolution, signal-to-noise ratio, and field of view (FOV) are investigated. Moreover, we develop a metalens array with polarization-multiplexed dual-phase design for a wide-field microscopic imaging. This approach remarkably expands the FOV without reducing the resolution, which promises a non-limited space-bandwidth product imaging for wide-field microscopy. As a result, we demonstrate a centimeter-scale prototype for microscopic imaging, showing uniqueness of meta-design for compact integration.

Highlights

Current imaging technology has been well developed by versatile strategies for outstanding performances in high resolution, high image quality, and broad wavelength band
After careful characterization of the imaging qualities with respect to the resolution, signal-to-noise ratio (SNR), FOV, and so on, we show the capability of this metalens-integrated imaging device (MIID) for spectral focal tuning[31] due to the large dispersion
In order to cover the blind area among limited FOV of our MIID in a single-shot imaging process, we proposed a polarization-multiplexed dual-phase (PMDP) metalens design with cross phase profiles of certain lens areas to satisfy the requirements of two different focusing lenses working at left-hand circular polarization (LCP) and right-hand circular polarization (RCP), respectively, as shown in Fig. 4(a)

Summary

Introduction

Current imaging technology has been well developed by versatile strategies for outstanding performances in high resolution, high image quality, and broad wavelength band. After careful characterization of the imaging qualities with respect to the resolution, signal-to-noise ratio (SNR), FOV, and so on, we show the capability of this metalens-integrated imaging device (MIID) for spectral focal tuning[31] due to the large dispersion It breaks the limitation of lens-free shadow imaging that cannot resolve the depth-of-field (DOF) of the object.[32] More importantly, we develop a metalens array to cover a wide area of CMOS image sensors for a wide-field imaging. We achieved high-resolution images (∼1.74 μm almost limited by image sensor pixel) with a millimeter-scale image area (expandable to whole centimeter-scale CMOS sensor), which was implemented in a ∼3-cm size device prototype This ultra-compact microscope system promises more exciting applications of metalens in high resolution, large FOV, and tunable DOF imaging

Device Architecture and Fabrication

Characterization of the Single Metalens Imaging

Wide-Field Imaging of MIID Integrated with PMDP Metalens Array

Discussions and Conclusion