The integration of a transimpedance amplifier in standard Silicon Photonics is presented. The circuit can successfully read integrated photodiodes up to a frequency of 2 MHz and down to −40 dBm of input optical power, demonstrating successful on-chip analog processing of electrical signals.

We present a transimpedance amplifier for on-chip optical power monitoring monolithically integrated into a pure Silicon Photonics platform, with no modifications to the fabrication process used by commercial foundries. The designed electronic circuit targets the conversion into voltage signals of the electrical current generated by integrated germanium photodiodes, performed directly on the photonic chip. The amplifier, with a transimpedance gain of 10 k Omega , has been characterized and validated to read light signals up to a frequency of 2 MHz and with an intensity down to about -40 dBm. The circuit is suitable for effectively monitoring the behaviour of photonic devices in a vast range of applications, without penalties in the optical functionality or additional fabrication costs. It thus represents a first demonstration of a more general analog electronics integration into pure Silicon Photonics, paving the way to complex on-chip elaboration and processing towards monolithic electronic control of large-scale optical circuits.

We present the integration of CMOS electronic circuits into a standard Silicon Photonics platform. The designed electronics, fabricated without modifying the fabrication process employed by commercial foundries, targets the detection and processing of electrical signals directly on the photonic chip. First, we show the operation of multiplexers and sample hold circuits for sequentially controlling large-scale photonic systems with few electrical signals. Then, we present the integration of a transimpedance amplifier for monitoring light signals down to −40 dBm with a frequency up to 2 MHz. These examples represent a first step towards complex electronic processing and elaboration in standard Silicon Photonics.

A generic antenna array design approach through multi-objective optimization is adopted to design a non-uniform optical thinned array (TA) satisfying a desired far-field pattern mask and minimizing the number of radiating elements. The proposed optical TA is integrated with a silicon photonic beamforming network (BFN) made of a mesh of tuneable Mach-Zehnder interferometer to implement a self-adaptive beam transmitter/ receiver for free-space optical (FSO) systems. Experimental results demonstrate the beam steering and shaping capability of the proposed architecture, which self-configures without any need for pre-calibration.

We present a novel optical sensor for light detection in photonic integrated circuits based on the photo-thermal plasmonic effect. We demonstrate its effectiveness in locking a Micro-Ring Resonator at resonance, using a control technique which is insensitive to crosstalk from thermal actuator to photo-thermal sensor.

This paper highlights the effectiveness of photo-thermal plasmonic sensors in enabling real-time closed-loop stabilization of photonic devices. To assess the waveguided optical power, the in-line detector leverages the photo-thermal resistance variation of a micrometric plasmonic strip in contact with the waveguide. The generated signal is used to lock to resonance a ring resonator against wavelength and temperature variations, in a silicon-based technology. Thanks to the high sensitivity of the detector and its limited penalty on the waveguide loss, automatic re-tuning of the ring resonator with a recovery time of 20 ms has been successfully achieved. The micrometric dimensions of the sensor, its technological simplicity, and the delivered signal (proportional to the optical power) make the photo-thermal plasmonic sensor an attractive in-line candidate for closed-loop control of optical devices, regardless of the technology employed for the photonic chip fabrication.

This work presents novel photo-thermal plasmonic sensors as inline quasi-transparent candidates for optical detection and control of photonic integrated circuits. The good sensitivity and resolution proved them successful in the stabilization of photonic devices against external perturbations. Thanks to their sub-wavelength dimensions and simple fabrication, these sensors are attractive in any platform, offering a solution for technologies that do not feature active optoelectronics.

This work demonstrates the ability of a silicon photonic mesh in recovering spectral information from chaotic light propagating through turbulent media. Results show-case the potential of the mesh in future LiDAR and communication applications.

Densely integrated photonic integrated circuits (PICs) require efficient solutions for monitoring the light intensity on chip in order to implement control and configuration operations to set and stabilize the working point of the circuit. To this end, waveguides supporting the propagation of surface plasmon polaritons (SPPs) are good candidates to realize small-footprint light detectors. In this work, we report on the realization of an in-line Surface Plasmon Detector (SPD) that exploits the photothermal effect to monitor the optical power in a titanium dioxide (TiO2) optical waveguide. Detailed design guidelines are provided to maximize the responsivity of the SPD, taking into account the effects of the metal geometry on the coupling between the dielectric and plasmonic modes, the power dissipated in the metal, and the equivalent thermal resistance of the structure. Experimental validation of the proposed device is provided demonstrating an ultra-compact 1.6- $\mu \text{m}$ -long SPD operating at a wavelength of 1550 nm with a sensitivity of–20 dBm and a bandwidth higher than 100 kHz. The proposed device concept can be ported to generic dielectric platforms and to other wavelength ranges where SPP propagation is supported.

Programmable photonic circuits require an electronic control layer to configure and stabilize the optical functionality at run‐time. Such control action is normally implemented by supervising the status of the circuit with integrated light monitors and by providing feedback signals to integrated actuators. This paper demonstrates that the control action can be effectively performed with electrical signals that are time‐multiplexed directly on the photonic chip. To this aim, the necessary electronic functionalities are monolithically integrated in a conventional 220 nm silicon photonics platform with no changes to the standard fabrication process. By exploiting a non‐conventional structure to implement metal‐oxide–semiconductor field‐effect transistors, an electronic controller is co‐designed into a programmable photonic circuit to enable a time‐multiplexed readout of integrated photodetectors and sequential activation of thermal phase shifters with on‐chip electronic memory. The accuracy of the time‐multiplexed control, achieved on a time scale of less than 10 ms, is demonstrated by penalty‐free routing of 10 Gbit s −1 modulated signals. This approach can be straightforwardly applied to large‐scale photonic chips to reduce the number of required electrical input/output connections.