SKM 2021 – scientific programme

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HL: Fachverband Halbleiterphysik

HL 8: Poster Session II

HL 8.24: Poster

Tuesday, September 28, 2021, 10:00–13:00, P

Ultra-high quality factor Ta2O5-on-insulator microring resonators with cryogenic temperature stability — •Julian Rasmus Bankwitz, Martin A. Wolff, Adrian Abazi, Alexander Eich, and Carsten Schuck — Institute of Physics University of Münster, Germany

Tantalum pentoxide (Ta2O5) on insulator is an emerging nanophotonic material system that benefits applications in nonlinear and quantum technology due to its outstanding optical properties [1]. As many implementations of quantum technology require cryogenic environments a need for low loss photonic integrated circuits with high temperature stability has arisen. Here we demonstrate ultra-high quality factor Ta2O5-on-insulator microring resonators with minimal temperature-dependent wavelength shift (TDWS). Through careful tuning of design and nanofabrication parameters, we achieve critically coupled devices with loaded quality factors of up to 1.8 Mio., observed over the entire range from room to cryogenic temperatures. The TDWS of ring resonances is as low as 237 pm from 1.74 K to 286 K and, remarkably, vanishes in the 110 K to 140 K range as it changes sign. Our Ta2O5-on-SiO2 devices will thus enable athermal operation of ultra-stable resonators as desired for wavelength division multiplexing, on-chip frequency stabilization and low-noise optical frequency combs.

[1] G. Moody et al. "Roadmap on Integrated Quantum Photonics," arXiv preprint arXiv:2102.03323, 2021.