Silicon photonic crystal cavity enhanced second-harmonic generation from monolayer WSe2

TL;DR

This paper demonstrates significant enhancement of second-harmonic generation in monolayer WSe2 using a silicon photonic crystal cavity, highlighting its potential for integrated nonlinear optical devices.

Contribution

It introduces a cavity-enhanced SHG technique in monolayer WSe2 with a silicon photonic crystal cavity, achieving a 200-fold increase in SHG efficiency.

Findings

SHG is enhanced by a factor of ~200 compared to bare monolayer.

Near-visible SHG with narrow linewidth and high polarization observed.

Potential for silicon-compatible nonlinear integrated photonics demonstrated.

Abstract

Nano-resonator integrated with two-dimensional materials (e.g. transition metal dichalcogenides) have recently emerged as a promising nano-optoelectronic platform. Here we demonstrate resonatorenhanced second-harmonic generation (SHG) in tungsten diselenide using a silicon photonic crystal cavity. By pumping the device with the ultrafast laser pulses near the cavity mode at the telecommunication wavelength, we observe a near visible SHG with a narrow linewidth and near unity linear polarization, originated from the coupling of the pump photon to the cavity mode. The observed SHG is enhanced by factor of ~200 compared to a bare monolayer on silicon. Our results imply the efficacy of cavity integrated monolayer materials for nonlinear optics and the potential of building a silicon-compatible second-order nonlinear integrated photonic platform.