Ultrafast-nonlinear ultraviolet pulse modulation in an AlInGaN polariton waveguide operating up to room temperature

TL;DR

This paper demonstrates ultrafast nonlinear modulation of ultraviolet pulses using AlInGaN polariton waveguides at room temperature, enabling compact on-chip UV spectroscopy applications.

Contribution

It introduces a novel UV polariton platform with giant nonlinearity, achieving ultrafast spectral broadening in a compact device, surpassing existing UV nonlinear materials.

Findings

Nonlinearity 1000 times greater than common UV materials

Ultrafast spectral broadening in 100 μm device

Operation at room temperature

Abstract

Ultrafast nonlinear photonics enables a host of applications in advanced on-chip spectroscopy and information processing. These rely on a strong intensity dependent (nonlinear) refractive index capable of modulating optical pulses on sub-picosecond timescales and on length scales suitable for integrated photonics. Currently there is no platform that can provide this for the UV spectral range where broadband spectra generated by nonlinear modulation can pave the way to new on-chip ultrafast (bio-) chemical spectroscopy devices. We demonstrate the giant nonlinearity of UV hybrid light-matter states (exciton-polaritons) up to room temperature in an AlInGaN waveguide. We experimentally measure ultrafast nonlinear spectral broadening of UV pulses in a compact 100 $\mu$m long device and deduce a nonlinearity 1000 times that in common UV nonlinear materials and comparable to non-UV polariton devices. Our demonstration promises to underpin a new generation of integrated UV nonlinear light sources for advanced spectroscopy and measurement.