Atomic layer deposited second order nonlinear optical metamaterial for back-end integration with CMOS-compatible nanophotonic circuitry

TL;DR

This paper demonstrates the fabrication of a CMOS-compatible nonlinear optical metamaterial using atomic layer deposition, achieving significant second-order nonlinearity suitable for integration into nanophotonic circuits.

Contribution

It introduces a novel atomic layer deposition technique to create unidimensional nonlinear metamaterials compatible with CMOS technology.

Findings

Effective bulk second-order nonlinearity of about 5 pm/V

Comparable to established nonlinear materials

Over an order of magnitude greater than similar previous reports

Abstract

We report the fabrication of artificial unidimensional crystals exhibiting an effective bulk second-order nonlinearity. The crystals are created by cycling atomic layer deposition of three dielectric materials such that the resulting metamaterial is non-centrosymmetric in the direction of the deposition. Characterization of the structures by second-harmonic generation Maker-fringe measurements shows that the main component of their nonlinear susceptibility tensor is about 5 pm/V which is comparable to well-established materials and more than an order of magnitude greater than reported for a similar crystal [1-Alloatti et al, arXiv:1504.00101[cond-mat.mtrl- sci]]. Our demonstration opens new possibilities for second-order nonlinear effects on CMOS-compatible nanophotonic platforms.