Integrated Buried Heaters for Efficient Spectral Control of Air-Clad Microresonator Frequency Combs

Published

November 22, 2022

Author(s)

Gregory Moille, Daron Westly, Edgar Perez, Meredith Metzler, Gregory Simelgor, Kartik Srinivasan

Abstract

Integrated heaters are a basic ingredient within the photonics toolbox, in particular for microresonator frequency tuning through the thermo-refractive effect. Resonators that are fully embedded in a solid cladding (typically SiO\textsubscript2}) allow for straightforward lossless integration of heater elements. However, air-clad resonators, which are of great interest for short wavelength dispersion engineering and direct interfacing with atomic/molecular systems, do not usually have similarly low loss and efficient integrated heater integration through standard fabrication. Here, we develop a new approach in which the integrated heater is embedded in SiO$_2$ below the waveguiding layer, enabling more efficient heating and more arbitrary routing of the heater traces than possible in a lateral configuration. We incorporate these buried heaters within a stoichiometric Si$_3$N$_4$ process flow that includes high-temperature ($>$1000$^\circ$C) annealing. Microring resonators with a 1THz free spectral range and quality factors near 10$^6$ are demonstrated, and the resonant modes are tuned by nearly 1.5THz, a 5$\times$ improvement compared to equivalent devices with lateral heaters Finally, we demonstrate broadband dissipative Kerr soliton generation in this platform, and show how the heaters can be utilized to aid in bringing relevant lock frequencies within a detectable range.

Citation

APL Photonics

Volume

7

Issue

12

Pub Type

Journals

Download Paper

https://doi.org/10.1063/5.0127466

Local Download

Keywords

frequency combs, nonlinear optics, soliton, nanophotonics, fabrication

Citation

Moille, G. , Westly, D. , Perez, E. , Metzler, M. , Simelgor, G. and Srinivasan, K. (2022), Integrated Buried Heaters for Efficient Spectral Control of Air-Clad Microresonator Frequency Combs, APL Photonics, [online], https://doi.org/10.1063/5.0127466 , https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=935393 (Accessed October 14, 2025)