  As photonics breaks away from today's device level toward large scale of
integration and complex systems-on-a-chip, concepts like monitoring, control
and stabilization of photonic integrated circuits emerge as new paradigms.
Here, we show non-invasive monitoring and feedback control of high quality
factor silicon photonics resonators assisted by a transparent light detector
directly integrated inside the cavity. Control operations are entirely managed
by a CMOS microelectronic circuit, hosting many parallel electronic read-out
channels, that is bridged to the silicon photonics chip. Advanced
functionalities, such as wavelength tuning, locking, labeling and swapping are
demonstrated. The non-invasive nature of the transparent monitor and the
scalability of the CMOS read-out system offer a viable solution for the control
of arbitrarily reconfigurable photonic integrated circuits aggregating many
components on a single chip.
