All semiconductor enhanced high-harmonic generation from a single nanostructured cone

Dominik Franz,Shatha Kaassamani,Ludovic Douillard,Nicolas Ducros,Liping Shi,Hamed Merdji,Sebastien Février,David Gauthier,Laure Lavoute,Willem Boutu,Jean-Thomas Gomes,Milutin Kovacev,Rana Nicolas,Jens Biegert,Maria Kholodtsova,Dmitry Gaponov

doi:10.1038/s41598-019-41642-y

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 applications such as petahertz electronics, nano-tomography or nano-medicine.

Highlights

The enhancement and control of non-linear phenomena at a nanometer scale has a wide range of applications in science and in industry
The principle is based on the confinement of the laser light in an integrated structure to reach the intensity threshold that allows for high-harmonic generation from a few nanojoules mid-infrared fiber laser
We have shown that high-harmonic generation can be confined in a single nanostructured semiconductor

Summary

Introduction

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 generation petahertz optoelectronic devices or compact all solid state EUV sources. This, in turn, allows to localize the HHG process in time at the single optical cycle scale[4] and in space at a nanometer scale to create for example beams that carry orbital angular momentum[11] This control can revolutionize attosecond science and prepare a new generation of ultrafast visible to X-ray optoelectronic devices operating at petahertz frequencies. Plasmonic resonances ensure extremely high enhancement of the local electric field with sub-diffraction-limited hot spots Another route for HHG enhancement is to use a full semiconductor structure. We illustrate the potential of the nanostructured cone to produce a nanosource of hot electrons

Methods

Results

Conclusion