Metasurface-Stabilized Optical Microcavities

TL;DR

This paper presents a novel method for stabilizing optical microcavities using amorphous silicon metasurfaces, achieving high quality factors and low losses at telecom wavelengths, with potential for scalable industrial applications.

Contribution

The study introduces a metasurface-based stabilization technique for optical microcavities, enabling arbitrary mode control and high performance at telecom wavelengths.

Findings

Achieved quality factors up to 4600 in telecom microcavities.

Limited metasurface scattering losses to less than 2%.

Enabled stabilization of arbitrary transverse modes and hologram modes.

Abstract

We demonstrate stable optical microcavities by counteracting the phase evolution of the cavity modes using an amorphous silicon metasurface as one of the two cavity end mirrors. Careful design allows us to limit the metasurface scattering losses at telecom wavelengths to less than 2% and using a distributed Bragg reflector as metasurface substrate ensures high reflectivity. Our first demonstration experimentally achieves telecom-wavelength microcavities with quality factors of up to 4600, spectral resonance linewidths below 0.4 nm, and mode volumes down to below 2.7$\lambda ^3$. We then show that the method introduces unprecedented freedom to stabilize modes with arbitrary transverse intensity profiles and design cavity-enhanced hologram modes. Our approach introduces the nanoscopic light control capabilities of dielectric metasurfaces to cavity electrodynamics and is directly industrially scalable using widespread semiconductor manufacturing processes.