Optical control of power devices: combining photonics, CMOS integration and monolithic integration for the next generation of power converters

International audienceEnergy savings and the reduction of CO2 gas emission are critical in our societies, towards a more sustainable future. For more than fifty years, power converters and power semiconductor devices have been continuously improved to reach the highest efficiency, the maximum reliable operation and the most compact solutions to adapt the electrical energy transfer between energy sources and loads. This is particularly true in electrical power distribution, smart grids, transportation and new mobility (e.g. Electric or hybrid vehicles, more electric or zero emission aircrafts, rail transport). Breakthroughs in power semiconductor devices such as GaN High Electron Mobility Transistors, SiC power MOSFETs and High Voltage Silicon power switches have pushed the specifications to an extreme level. As an example, the switching speed of GaN power transistors can be higher than 200V/ns, leading to extremely low switching losses, decade-higher switching frequencies, albeit with an unprecedented stress in terms of Electromagnetic Interferences (EMI). Moreover, power converters necessitate many power transistors, each needing a specific isolated gate driver to control the switching transitions. Although optical isolation has been used for a long time in power electronics, mainly with discrete opto-electronics devices, integrated microwave photonics was never considered in the related applications