Premium
Bricked Subwavelength Gratings: A Tailorable On‐Chip Metamaterial Topology
Author(s) -
LuqueGonzález José Manuel,
OrtegaMoñux Alejandro,
Halir Robert,
Schmid Jens H.,
Cheben Pavel,
MolinaFernández Íñigo,
WangüemertPérez J. Gonzalo
Publication year - 2021
Publication title -
laser and photonics reviews
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.778
H-Index - 116
eISSN - 1863-8899
pISSN - 1863-8880
DOI - 10.1002/lpor.202000478
Subject(s) - metamaterial , materials science , lithography , optoelectronics , fabrication , photonics , bandwidth (computing) , optics , wafer , computer science , physics , telecommunications , medicine , alternative medicine , pathology
Integrated metamaterials are redefining the capabilities of silicon photonic chips. In providing lithographic control over dielectric permittivity, dispersion and anisotropy, they are enabling photonic devices with unprecedented performance. However, the implementation of these materials at telecom wavelengths often requires a fabrication resolution of the order of 100 nm and below, pushing current wafer‐scale fabrication technology to its limits and hindering the widespread exploitation of on‐chip metamaterials. Herein, a subwavelength grating metamaterial with bricked topology is proposed, that provides lithographic control over the metamaterial dispersion and anisotropy using a single etch Manhattan‐like geometry with pixel dimensions up to 150 × 150 nm 2 , thereby easing the path toward fabrication at wafer‐scale. The behavior of these structures as biaxial crystals is analytically shown, validating their use in high performance on‐chip beam‐splitters. Through engineering of the metamaterial anisotropy tensor, the splitters are shown to exhibit sub‐decibel insertion losses and imbalance over a 400 nm design bandwidth, via 3D FDTD simulations. The excellent device performance is demonstrated over a 140 nm bandwidth, limited by the measurement setup.