Our research in silicon photonics focuses on non-conventional devices as well as at the system level. We design our devices, simulate their performances and fabricate them at the Nano3 cleanroom. We also perform cutting edge applied research in photonics circuits using industrial foundries through Multi-Project Wafer (MPW) runs. We perform in-depth characterizations using the state-of-the-art equipment available in our labs. The targeted applications of our works includes spectroscopy, telecommunication, and microwave photonics to name of few.
Fourier transform spectrometer on silicon with thermo-optic non-linearity and dispersion correction
Miniaturized integrated spectrometers will have unprecedented impact on applications ranging from unmanned aerial vehicles to mobile phones, and silicon photonics promises to deliver compact, cost-effective devices. Mirroring its ubiquitous free-space counterpart, a silicon photonics-based Fourier transform spectrometer (Si-FTS) can bring broadband operation and fine resolution to the chip scale. Here we present the modeling and experimental demonstration of a thermally tuned Si-FTS accounting for dispersion, thermo-optic non-linearity, and thermal expansion. We show how these effects modify the relation between the spectrum and interferogram of a light source and we develop a quantitative correction procedure through calibration with a tunable laser. We retrieve a broadband spectrum (7 THz around 193.4 THz with 0.38-THz resolution consuming 2.5 W per heater) and demonstrate the Si-FTS resilience to fabrication variations—a major advantage for largescale manufacturing. Providing design flexibility and robustness, the Si-FTS is poised to become a fundamental building block for on-chip spectroscopy.