Impact of the precursor gas ratio on dispersion engineering of broadband silicon nitride microresonator frequency combs
Abstract
Microresonator frequency combs, or microcombs, have gained wide appeal for their rich nonlinear physics and wide range of applications. Stoichiometric silicon nitride films grown via low-pressure chemical vapor deposition (LPCVD), in particular, are widely used in chip-integrated Kerr microcombs. Critical to such devices is the ability to control the microresonator dispersion, which has contributions from both material refractive index dispersion and geometric confinement. Here, we show that modifications to the ratio of the gaseous precursors in LPCVD growth have a significant impact on material dispersion and hence the overall microresonator dispersion. In contrast to the many efforts focused on comparisons between Si-rich films and stoichiometric ( S i 3 N 4 ) films, here, we focus on films whose precursor gas ratios should nominally place them in the stoichiometric regime. We further show that microresonator geometric dispersion can be tuned to compensate for changes in the material dispersion.
Document Details
- Document Type
- Pub Defense Publication
- Publication Date
- Nov 29, 2021
- Source ID
- 10.1364/ol.440907
Entities
People
- Daron Westly
- Gregory Simelgor
- Grégory Moille
- Kartik Srinivasan
Organizations
- Defense Advanced Research Projects Agency
- National Institute of Standards and Technology
- National Science Foundation
- University of Maryland