Observation of Transparency of Erbium-doped Silicon nitride in photonic crystal nanobeam cavities

TL;DR

This study demonstrates the transparency of Erbium-doped silicon nitride in photonic crystal nanobeam cavities through photoluminescence and linewidth narrowing, indicating potential for integrated photonic devices.

Contribution

First observation of Erbium-doped silicon nitride transparency in nanobeam cavities using photoluminescence and linewidth analysis.

Findings

Purcell enhancement observed in emission rates

Linewidth narrowing indicates absorption bleaching

Evidence of stimulated emission at room temperature

Abstract

One-dimensional nanobeam photonic crystal cavities are fabricated in an Er-doped amorphous silicon nitride layer. Photoluminescence from the cavities around 1.54 um is studied at cryogenic and room temperatures at different optical pump powers. The resonators demonstrate Purcell enhanced absorption and emission rates, also confirmed by time-resolved measurements. Resonances exhibit linewidth narrowing with pump power, signifying absorption bleaching and the onset of stimulated emission in the material at both 5.5 K and room temperature. We estimate from the cavity linewidths that Er has been pumped to transparency at the cavity resonance wavelength.