Electromagnetically induced transparency and wide-band wavelength conversion in silicon nitride microdisk optomechanical resonators

TL;DR

This paper demonstrates electromagnetically-induced transparency and wide-band wavelength conversion in silicon nitride microdisk resonators, enabling coherent optical signal manipulation across a broad wavelength range with high quality factors.

Contribution

The work introduces a novel silicon nitride microdisk platform supporting wide-band wavelength conversion via optomechanical interactions in the resolved sideband regime.

Findings

Achieved EIT and wavelength conversion in Si3N4 microdisks

Demonstrated frequency span of 69.4 THz between 1300 nm and 980 nm

Supported multiple optical modes coupled to the same mechanical mode

Abstract

We demonstrate optomechanically-mediated electromagnetically-induced transparency and wavelength conversion in silicon nitride (Si3N4) microdisk resonators. Fabricated devices support whispering gallery optical modes with a quality factor (Q) of 10^6, and radial breathing mechanical modes with a Q=10^4 and a resonance frequency of 625 MHz, so that the system is in the resolved sideband regime. Placing a strong optical control field on the red (blue) detuned sideband of the optical mode produces coherent interference with a resonant probe beam, inducing a transparency (absorption) window for the probe. This is observed for multiple optical modes of the device, all of which couple to the same mechanical mode, and which can be widely separated in wavelength due to the large bandgap of Si3N4. These properties are exploited to demonstrate frequency upconversion and downconversion of optical signals between the 1300 nm and 980 nm bands with a frequency span of 69.4 THz.