Understanding precisely how light behaves as it moves through devices such as solar cells or optical chips will lead to more efficient devices–and reveal new physical phenomena that engineers can exploit. To this end, theoretical physicist Michelle Povinelli is creating models of how photons interact with complex materials.
In one surprising finding, Povinelli correctly predicted that light being guided down a strip of silicon would exert a mechanical force on an adjacent strip. If moving parts driven by light were incorporated into optical circuits and used to reroute light signals, the light might not have to be converted into electricity for processing and then back to light again.
Making better solar cells may sound very different from optical communications, but understanding how light interacts with a device is equally important in this context. Povinelli is working on models to predict the efficiency of solar cells that have different nanostructures. Finding the ultimate efficiency for these cells will set a boundary on what researchers can hope to achieve and guide them toward photovoltaics that are less expensive but much better at generating electricity. –Katherine Bourzac