Session Index

Vacuum ultraviolet (VUV) light is essential to practical applications ranging from nanolithography, biosensing, and spectroscopy. However, it is usually challenging to realize efficient and compact VUV devices. In this work, we report a metalens consisting of ZnO nanoantennas for nonlinear light generating and focusing 197-nm VUV light.

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Meta-optics is the subject of growing interest recently; however, some of research are emphasized the efficiency of the metasurfaces itself. Substrate with low refractive materials (e.g., glass) are selected without considering the refractive index matching problem for a compact integration with lasers. To increase efficiency, here, we design our meta-grating as homo-grating, aka same material for the meta-atoms, the substrate, and the top layer of the laser, to avoid mismatch issue. We achieve absolute efficiency more than 50% at a deflection angle ~60°. We envision that our approach can be implemented in various applications, including light detection and ranging (LiDAR).

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Because metasurface is smaller than traditional optical components, many practical applications have begun to appear. Image sensors are an example. Since the lens CMOS sensor cannot distinguish colors, a color filter must be added to distinguish the received colors. However, the efficiency also decreased, so metalens with energy harvesting began to attract attention. This paper introduces metalens with energy harvesting. Through good energy sorting performance, more NIR energy can be collected without affecting the RGB band. If applied to The monitoring system will provide a non-negligible change to the recognition ability at night.

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Metasurfaces, a catalog of optical component, have numerous novel functions on demand. This kind of optical component integrated with vertical cavity surface emitting laser (VCSEL) has been reported. However, the performance is limited by VCSEL features and metasurface designed, such as low output power, large divergence angle. Here, we experimentally demonstrate a holographic image generation from a compact integration of photonics crystal surface emitting laser (PCSEL) and metasurface hologram. This research shows high output power (mW level), free from collection-lens and well image uniformity with wide field of view (FOV), these features are suitable for 3D imaging and 3D sensing.

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We propose plasmonic vortex lens (PVL) 4-arms with circular groove (CG) design to manipulate microparticle in the near field or far field depending on the handedness of circular polarization. The optical properties and trapping performances of the structure are simulated and analyzed. A Polystyrene (PS) bead of 1 diameter can be trapped in the near-field region (0.47λ) under left-handed circular polarization (LCP) illumination with minimum required power of 0.4 mW. Under right-handed circular polarization (RCP) illumination, the particle will be rotated in the far-field region (0.94λ) with minimum required power of 14.9 mW.

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In this paper, we propose an integrated configuration of subwavelength apertures for simultaneous color filtering in a spectral range from the visible to the near-infrared range. The incident light wave coupled with the hybrid nanostructures may result in the surface plasmons propagation through the integrated configuration as a flat lens, generating transmissive and reflective beams with suppressed cross-talk and high spectral resolution. We analyzed the transmission characteristics of the nanostructure color filters by using the finite-different time-domain algorithm. Furthermore, the polarization states and beam propagation direction may be altered with the asymmetric nanostructures in prospective applications.

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Janus metasurfaces provide more functionalities to harness the light with different incident direction as degree of freedom. And directional Janus metasurfaces have been demonstrated at the microwave and near infrared region previously. However, such Janus metasurfaces are designed with multi-layers which cause complex fabrication process. Besides, Janus metasurfaces operating in the optical frequencies play more important role. In this study, we present a design of TiO2 monolayer Janus metasurface which generate different states of orbital angular momentum (OAM) in the visible. Direction-tunable arbitrary vortex beam expands the scope of polarization optics, enables compact and versatile total angular momentum operations.

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The resonant waveguide gratings (RWGs) with in and out couplers have been demonstrated to perform selective color-filtering and beam steering. However, RWGs with forward design suffers lower efficiency that limit the applications. Here, we design a metasurface which composed of titanium dioxide RWGs on the glass substrate working at red, green, and blue wavelengths, simultaneously. And we improve the diffraction efficiency by using adjoint-based topology optimization. The diffraction efficiency of simulation is up to 75% with the Q-factor reaching 320. Such a beam steering device opens a new paradigm for applications, including see-through optical combiners and augmented reality platforms.

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