IEEE J. Sel. Top. Quantum Electron. 20, 8201710 (2014)
In large-scale photonic integration, it is important to perform circuit monitoring and feedback control of devices to counteract fabrication tolerances, environmental fluctuations and crosstalk effects. An on-chip non-invasive detector that could inspect the light inside optical waveguides without altering its propagation state would be very useful for this purpose. Now, Francesco Morichetti and co-workers in Italy and the UK have demonstrated exactly that. Their contactless integrated photonic probe (CLIPP) is a few hundred micrometres in size and is fabricated on a silicon photonic platform that is compatible with complementary metal–oxide–semiconductor technology. The device works by monitoring the change in the waveguide conductance induced by the interaction of photons with intra-gap energy states localized at the waveguide's silicon–silicon oxide interface. Capacitive access to the waveguide is exploited to avoid direct contact with the waveguide core. Measurements with a dynamic range of 40 dB and a sensitivity as low as −30 dBm in waveguides and high-Q resonators were reported. The probe could prove useful for various applications, including telecommunications, optical interconnects, biosensing, and quantum manipulation and computing.
Rights and permissions
About this article
Cite this article
Won, R. Stalking light. Nature Photon 8, 266 (2014). https://doi.org/10.1038/nphoton.2014.64