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arXiv · 2511.16490

Tunable integrated ring resonators by femtosecond laser micromachining

Giulio Gualandi·Fabio Saretto·Daniele Pedroli·Giacomo Corrielli·Marco Liscidini·Roberto Osellame·Andrea Crespi
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Abstract

Femtosecond Laser Micromachining (FLM) is a powerful technology for the fabrication of photonic devices. In this context, the integration of resonant elements within the platform represents a key advancement, enhancing both its versatility and its compatibility with a wide range of optical and fluidic components specifically enabled by this technique. Here, we report the realization of a tunable racetrack resonator fabricated by FLM and operating at telecom wavelengths. Leveraging low-loss waveguides, we obtained a Q factor of the resonator as high as 8 x 10^5 at critical coupling. Moreover, by integrating two thermo-optic phase shifters, we achieved both resonance tuning and dynamic control of the Q factor. This capability makes the device highly versatile for applications requiring dynamic spectral control, such as tunable filters, gyroscopes, and sensors.

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Giulio Gualandi, Fabio Saretto, Daniele Pedroli, Giacomo Corrielli, Marco Liscidini, Roberto Osellame, Andrea Crespi. 2025-11-20. Tunable integrated ring resonators by femtosecond laser micromachining. https://arxiv.org/abs/2511.16490

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