The University of Southampton’s Silicon Photonics group announced the publication of its paper on “Harnessing plasma absorption in silicon MOS ring modulators” in the prestigious Nature Photonics journal.
The researchers have shown that absorption during the plasma-dispersion effect can be harnessed to enhance the performance of silicon MOS ring modulators.
The work was performed within a Prosperity Partnership project jointly funded by the Engineering and Physical Sciences Research Council (EPSRC) and collaborator Rockley Photonics.
Dr Weiwei Zhang, Senior Research Fellow at the Optoelectronics Research Centre (ORC), explains: “Silicon MOS ring modulators convert electrical signals into optical signals. This is based on the plasma-dispersion effect, where if you increase the concentration of electrons and holes in the waveguide, you get a phase shift of the light, as well an increase in absorption. Until now the absorption part has been considered unwanted as it increases the overall device loss and so you get less light afterwards.”
“Our work shows that you can use the absorption to push the modulators to perform better for the same device capacitance. As a result, we have also managed to demonstrate the fastest data transmission recorded on a device of this type so far up to 100 Gbit s−1.”
“One of our main research focuses is to continually push the performance of optical modulators in silicon photonics. Whilst there has been a worldwide trend to introduce other materials to do this, CMOS compatibility can be compromised potentially leading to higher production costs. Here we have shown that there are still ways to enhance the performance of all-silicon based devices that can be fabricated at relatively low cost.”
