On-Chip Optical Beam Manipulation with an Electrically Tunable Lithium-Niobate-on-Insulator Metasurface

Abstract

Photonic integrated circuits (PICs) have garnered increasing attention because of their high efficiency in information processing. Recently, lithium niobate on insulator (LNOI) has become a new platform for PICs with excellent properties. Several tunable devices such as on-chip tunable devices that utilize the electric-optic effect of LN have been reported. However, an on-chip electrically tunable beam modulator that can focus or deflect the wave has not yet been developed. In this study, we designed an electrically tunable LNOI metasurface for on-chip optical beam manipulation. With a carefully designed local phase profile, we realized the tunable focusing and reflection functions on the chip. As the bias voltage varies, the focusing length can be shifted up to 19.9 μm (~13λ), whereas the focusing efficiency remains greater than 72%. A continuously tunable deflection can also be achieved efficiently within a range of 0–45°. The beam modulator enhances the ability to manipulate light on LNOI chips, which is expected to promote the development of integrated on-chip photonics.

On-chip programmable optical routing using nonvolatile Sb2Se3 phase-change metasurfaces

“…Metasurfaces are arrays of subwavelength structures capable of shaping the wavefront (phase) of incident light. On-chip one-dimensional (1D) metasurfaces provide an innovative approach to on-chip wavefront shaping [16][17][18][19][20][21][22][23][24][25][26][27][28][29][30][31]. On-chip one-dimensional metasurface-based systems can operate without alignment step but limited to process one-dimensional data.…”

Editorial for the Special Issue on Tunable Nanophotonics and Reconfigurable Metadevices

“…This Special Issue, entitled “Tunable Nanophotonics and Reconfigurable Metadevices”, includes some remarkable studies: four research articles and one review article. The issue covers a wide range of topics: tunable localized surface plasmon resonance (LSPR) in Ag nanobars [ 1 ], electrically tunable lithium niobate on an insulator (LNOI) metasurface for on-chip optical beam control [ 2 ], on-chip metasurface-based quantum analog devices [ 3 ], a bifunctional reconfigurable metalens made from phase-change materials [ 4 ], and a review of recent advances in optical metasurface research [ 5 ]. From the perspective of basic optical properties, Wu et al [ 1 ] reported the study of LSPR in synthesized large-size Ag nanobars (length: 400~1360 nm) working in a longer near-infrared wavelength range (>1000 nm).…”

“…The LSPR in an Ag nanobar can be flexibly tuned in a wide wavelength range (400~2000 nm) by changing the geometry of the nanostructure. From the perspective of optical functionality, Dou et al [ 2 ] propose an electrically tunable LNOI metasurface for on-chip optical beam manipulation, where dynamic focusing function and deflection function are demonstrated on a metasurface with varying voltages, considering the electro-optic effect of lithium niobate. Wei et al [ 3 ] proposed an on-chip quantum searcher based on a silicon-on-insulator (SOI) structure, which comprises four on-chip metasurfaces with controlled transmitted intensity and phase profiles for simulating a quantum search algorithm.…”