While the field of plasmonics may sound esoteric, it is based on some fairly straightforward physics and, when applied to devices, could alter photonics dramatically. It involves exploiting the waves of electrons—known as surface plasmons—that are triggered when light (photons) strikes a metal surface. The length of these plasmon waves is much shorter than the wavelengths of light, making it possible to use light indirectly in the very small dimensions of today’s integrated circuits.
By transforming wavelengths of light into waves of electrons, it has become possible for scientists to merge the speed of optics with the dimensions of electronic devices. However, plasmonics has remained mired in a proof-of-concept state despite many practical devices having been experimentally demonstrated for on-chip circuitry.
Now, an international team of researchers has developed a switch for plasmonic devices that could eventually lead to a CMOS-compatible material platform for making practical plasmonic circuits.
In research described in the journal Nature, researchers at Purdue University in collaboration with those from ETH Zürich, the University of Washington, and Virginia Commonwealth University, have created a switch in the form of a ring modulator for a plasmonic-based circuit that uses resonance—or a vibration—to control whether photons interact with surface plasmons, or not. This switch should overcome a key problem for these circuits: the light used within them can be absorbed by surface plasmons—a property known as “loss.”