Bidirectional nanoprinting based on bilayer metasurfaces

Abstract

Bidirectional nanoprinting, has received significant attention in image display and on-chip integration, due to its superior advantages. By manipulating the amplitude in a narrow- or broad-band wavelength range of forward and backward incident light, different spatially varied intensities or color distributions can be generated on the structure plane. However, the current scheme cannot fully decouple the bidirectional light intensity due to the limitation of design degree of freedom, and it would hinder the development of asymmetric photonic devices. In this paper, we propose and demonstrate bidirectional nanoprinting based on an all-dielectric bilayer metasurface, which can independently control the intensity of forward and backward incident light, resulting in two different continuous grayscale meta-image displaying in the visible region. This asymmetric but still bidirectional optical response is introduced by stacking two layers of nanostructures with different functionality in space, in which the first- and second-layer nanostructures act as a half-wave plate and a polarizer, respectively. Interestingly, these bidirectional nanoprinting metasurfaces have flexible working modes and may bring great convenience for practical applications. Specifically, two different meta-images generated by a bidirectional nanoprinting metasurface can be displayed not only on two sides of the metasurface (working mode in transmission or reflection), but on the same side due to the forward transmitted light and backward reflected light also having asymmetric optical properties. Similar phenomena also exist for forward reflected light and backward transmitted light. Our work extremely expands the design freedom for metasurface devices and may play a significant role in the field of optical display, information multiplexing, etc.

Metasurface-based nanoprinting: principle, design and advances

“…Information multiplexing can make the maximal use of existing hardware facilities to improve the information capacity as much as possible without increased costs. For metasurfaces, with the aid of wavelength multiplexing 57−59 , angular multiplexing 60,61 , spatial frequency multiplexing 62 , propagation direction multiplexing 63 and polarization multiplexing 64−78 , multiple channels carrying different nanoprinting-image information can be recorded into one single metasurface, thus increasing the information capacity of meta-devices. Usually, information channels can be optically switched by altering the optical parameters, such as incident angle, wavelength, polarization and so on.…”

Ultrathin Suspended Chiral Metasurfaces for Enantiodiscrimination

“…Moreover, the asymmetric transmission properties may find potential applications in information processing, polarimetric imaging and encryption. [49,[53][54][55][56][57][58]…”

“…Layered metasurface systems with nonreciprocal propagation properties resulting from their inherent out-of-plane asymmetry have received significant attention for specific functionalities, such as one-way focusing, direction-controlled holograms, and encryption in optics. [53][54][55][56] Our proposed structure also exhibits an asymmetric transmission property, which could be applied to transmit and process optical signals selectively in the future. [57,58] Furthermore, we employ the suspended chiral bilayer metasurfaces as a platform for label-free sensing of the chiral biomolecules.…”

All-silicon and ultra-compact transverse electric-pass polarizer with large bandwidth and high polarization extinction ratio based on subwavelength metamaterials

“…Many optical systems, such as bi-directional nano printing systems, 1 hyperspectral imaging systems, 2 and optical gyroscopes systems, 3 require polarizers with high polarization extinction ratio (PER) to minimize polarization crosstalk. With the development of the micro-nano fabrication, optical systems are pursuing smaller volume.…”