A SiGe Slot Approach for Enhancing Strain Induced Pockels Effect in the Mid-IR Range

Strained silicon was proposed more than a decade ago promising to revolutionize the silicon photonics field by allowing efficient modulation in this platform. Despite all the efforts, still rather low χ(2) values have been measured in strained silicon devices. In addition, the way of applying strain has not barely changed since the concept was proposed, usually consisting on a silicon waveguide covered by a stressor material such as silicon nitride. In this letter, a SiGe slot approach is explored as a different route to enhance the strain induced Pockels effect in the mid-IR range. Such approach would allow effective index change values which are near to 10 ^-4 and improve the values expected for the most common silicon - silicon nitride structure by more than three orders of magnitude.