All-optical modulation in wavelength-sized epsilon-near-zero media

TL;DR

This paper demonstrates that epsilon-near-zero (ENZ) media can enable highly efficient all-optical modulation within a wavelength-thick slab, due to their extreme sensitivity near the ENZ wavelength.

Contribution

It reveals the potential of ENZ materials for all-optical modulation, showing dramatic transmission changes when the probe is tuned to the ENZ wavelength, a novel application of ENZ properties.

Findings

Significant transmission modulation occurs when the probe is at the ENZ wavelength.

Modulation efficiency is high enough to occur in a wavelength-thick slab.

Non-ENZ probes are unaffected by the pump, demonstrating selectivity.

Abstract

We investigate the interaction of two pulses (pump and probe) scattered by a nonlinear epsilon-near-zero (ENZ) slab whose thickness is comparable with the ENZ wavelength. We show that when the probe has a narrow spectrum localized around the ENZ wavelength its transmission is dramatically affected by the intensity of the pump. Conversely, if the probe is not in the ENZ regime, its propagation is not noticeably affected by the pump. Such all-optical modulation is due to the oversensitive character of the ENZ regime and it is so efficient to even occur in a wavelength thick slab.