Modern complex photonic circuits have to be equipped with a control-loop to compensate for unavoidable fabrication uncertainties and to re-configure the device upon the needs. The more the photonic circuit is complex, the higher the number of actuators/sensors. And thus, the number of pads to be electrically accessed. Here a high-density opto-electronic probe card is described and exploited to perform electrical tests on complex silicon photonic circuits. The last part of the chapters is dedicated to the management of thermal cross-talk in case the exploited actuators rely on thermal effects.