Experimental parameter study of thermally tunable Mach-Zehnder switches

Mach-Zehnder interferometers (MZIs) are key components of modern photonic circuits, with applications ranging from optical computing and artificial intelligence to sensing and quantum optics. These applications increasingly require complex networks of MZIs that operate efficiently over a broad frequency range, with low insertion loss and minimal power consumption.

In a recent study, Jens Samland and colleagues demonstrate that precisely tunable MZIs can be realized on silicon-on-insulator (SOI) substrates using a CMOS-compatible fabrication process. The results have been published in Optics Continuum and highlighted as an Editor’s Pick for their scientific excellence.

The focus of the work is a comprehensive experimental parameter study aimed at optimizing thermal tuning. The researchers investigated how the distance between the heater and the interferometer, as well as the width of the heater, affect heating efficiency and switching speed. They also analyzed how the footprint of the interferometer impacts its overall performance.

The experimental results show excellent agreement with simulations performed using Ansys Lumerical, confirming the technical feasibility of fabricating thermally tunable MZIs with high efficiency and reproducible characteristics in a scalable and industry-compatible process — a significant step forward for integrated photonic systems.

This research was funded by the German Federal Ministry of Education and Research (BMBF) as part of the QSPEC and NeuroSys Cluster projects.

Bibliographic information

“Experimental parameter study of thermally tunable Mach-Zehnder switches”

Jens Samland, Bartos Chmielak, Jens Bolten, Stephan Suckow, Thorsten Wahlbrink, and Max C. Lemme

Optics Continuum 2025

https://opg.optica.org/optcon/fulltext.cfm?uri=optcon-4-3-561&id=568662