Inverse Design of Whispering-gallery Nanolasers with Tailored Beam Shape and Polarization

TL;DR

This paper introduces an inverse design method for monolithic whispering-gallery nanolasers that can emit beams with specific shapes and polarizations, verified through experimental prototypes.

Contribution

It presents a novel inverse design approach for creating ultra-compact nanolasers with customizable beam shapes and polarization states, validated by experimental results.

Findings

Achieved high mode overlap: 92%, 96%, and 85% for different beam types.

Demonstrated the generality of the design method across multiple laser modes.

Fabricated and verified three distinct nanolaser prototypes.

Abstract

Control over the shape and polarization of the beam emitted by a laser source is important in applications such as optical communications, optical manipulation and high-resolution optical imaging. In this paper, we present the inverse design of monolithic whispering-gallery nanolasers which emit along their axial direction with a tailored laser beam shape and polarization. We design and experimentally verify three types of sub-micron cavities, each one emitting into a different laser radiation mode: an azimuthally polarized doughnut beam, a radially polarized doughnut beam and a linearly polarized gaussian-like beam. The measured output laser beams yield a field overlap with respect to the target mode of 92%, 96% and 85% for the azimuthal, radial and linearly polarized cases, respectively, thereby demonstrating the generality of the method in the design of ultra-compact lasers with tailored beams.