Directional lasing at high oblique angle from metasurface exhibiting multivalley dispersion

TL;DR

This paper demonstrates a metasurface laser emitting at high oblique angles using multivalley dispersion, enabling novel applications in integrated photonics and valleytronic physics at telecom wavelengths.

Contribution

It introduces a metasurface laser that exploits multivalley dispersion for directional emission at high angles, a novel approach in integrated photonics.

Findings

Lasing occurs at high oblique angles (~20 degrees) at telecom wavelengths (~1580 nm).

The metasurface operates at room temperature on a silicon substrate.

Potential applications include beam steering and valleytronic physics studies.

Abstract

We report on a metasurface laser emitting at the valley extremum of a multivalley energy-momentum dispersion. Such peculiar dispersion shape is obtained by hybridizing high quality factor photonic modes of different symmetry and opposite effective mass. The lasing effect takes place at high oblique angle ($\sim$20 degrees), in the telecom wavelength range ($\sim$1580 nm), on silicon substrate and operating at room temperature. Our results show the potential of multivalley dispersion for micro-laser in integrated photonic and beam-steering applications. It also opens the way to study various features of valleytronic physics such as spontaneous momentum symmetry breaking, two-mode squeezing and Josephson oscillation in momentum space.