All semiconductor enhanced high-harmonic generation from a single nano-structure

TL;DR

This paper reports the development of the first nanoscale high harmonic source using a single semiconductor nano-structure, enabling compact UV/X-ray nanoprobes for advanced scientific and industrial applications.

Contribution

It introduces a novel semiconductor nano-structure that generates high harmonics at the nanoscale, demonstrating enhancement and control of non-linear phenomena in a compact device.

Findings

Achieved strong field regime in a single 3D semiconductor waveguide.

Observed enhancement of harmonic emission far from the band edge.

Demonstrated potential applications in nano-imaging and petahertz electronics.

Abstract

The enhancement and control of non-linear phenomena at a nanometer scale has a wide range of applications in science and in industry. Among these phenomena, high-harmonic generation in solids is a recent focus of research to realize next generation petahertz optoelectronic devices or compact all solid state EUV sources. Here, we report on the realization of the first nanoscale high harmonic source. The strong field regime is reached by confining the electric field from a few nanojoules femtosecond laser in a single 3D semiconductor waveguide. We reveal a strong competition between enhancement of coherent harmonics and incoherent fluorescence favored by excitonic processes. However, far from the band edge, clear enhancement of the harmonic emission is reported with a robust sustainability offering a compact nanosource for applications. We illustrate the potential of our harmonic nano-device by performing a coherent diffractive imaging experiment. Ultra-compact UV/X-ray nanoprobes are foreseen to have other potential applications such as petahertz electronics, nano-tomography or nano-medicine.