Deuterated silicon nitride photonic devices for broadband optical frequency comb generation

TL;DR

This paper introduces low-temperature plasma-deposited deuterated silicon nitride films for integrated nonlinear photonics, achieving high-quality microresonators and broadband frequency combs compatible with CMOS processes.

Contribution

It demonstrates a CMOS-compatible, low-temperature fabrication process for deuterated silicon nitride photonic devices with high quality factors and broadband comb generation capabilities.

Findings

Microresonators with Q up to 1.6 million at 1552 nm

Generation of 1 THz free spectral range Kerr comb

Octave-spanning supercontinuum spectra achieved

Abstract

We report and characterize low-temperature, plasma-deposited deuterated silicon nitride thin films for nonlinear integrated photonics. With a peak processing temperature less than 300$^\circ$C, it is back-end compatible with pre-processed CMOS substrates. We achieve microresonators with a quality factor of up to $1.6\times 10^6 $ at 1552 nm, and $>1.2\times 10^6$ throughout $\lambda$ = 1510 -- 1600 nm, without annealing or stress management. We then demonstrate the immediate utility of this platform in nonlinear photonics by generating a 1 THz free spectral range, 900-nm-bandwidth modulation-instability microresonator Kerr comb and octave-spanning, supercontinuum-broadened spectra.