New Kind of Switch Uses a Gold Disk to Catch Light Waves

Microscopic switches that transmit light signals amidst computer chips like tiny traffic conductors could help make faster, more effective electronics.
Light waves can carry instructions more efficiently than the electric current used in established circuitry, because atoms of light called photons zip through materials without communicating with their ambience as much as electrons. But till now, mechanical switches designed to shape such data-carrying light waves have run comparatively slowly and required unrealistic high electric voltages to work.
Electronics outfitted with the new switch design to process data with light rather than electricity could help self-driving cars scan their surroundings for traffic and pedestrians or read out information from quantum computers.
Each switch comprises an ultrathin gold disk suspended above a silicon plate. Applying a small voltage across the switch forces the gold disk to bend upward like a bowl, or bow downward like an umbrella. The gold disk’s orientation at any given time controls whether light flowing through a nearby wirelike structure called a waveguide continues uninterrupted or gets rerouted.

As light in the waveguide passes by the switch, some light leaks into a racetrack-shaped gap between the gold disk and the silicon plate, whips around the track and recombines with light in the waveguide. If the gold plate is curved upward, the peaks and valleys of light waves that exit the track align with those in the waveguide — reinforcing the light along its original path.
But if the gold plate is bent down toward the silicon plate, interactions with electrons in the gold delay light as it travels around the racetrack. That causes the valleys of light waves exiting the track to coincide with the peaks of waves flowing through the waveguide, canceling each other out and blocking the flow of light along its original course. As light in the waveguide passes by the switch, some light leaks into a racetrack-shaped gap between the gold disk and the silicon plate, whips around the track and recombines with light in the waveguide. If the gold plate is curved upward, the peaks and valleys of light waves that exit the track align with those in the waveguide — reinforcing the light along its original path.
But if the gold plate is bent down toward the silicon plate, interactions with electrons in the gold delay light as it travels around the racetrack. That causes the valleys of light waves exiting the track to coincide with the peaks of waves flowing through the waveguide, canceling each other out and blocking the flow of light along its original course.

By – Abhishek Singh
Content - https://www.sciencenews.org/article/tiny-switch-redirects-light-between-computer-chips-nanoseconds