Rod-shaped waveguide with two quasi-two dimensional conformal coatings that shield the waveguide from crosstalk and blocking and allow the waveguide to be smaller. (Credit: Werner Lab/Penn State)

A team of electrical engineers have developed a way to simultaneously control diverse optical properties of dielectric waveguides by using a two-layer coating, each layer with a near zero thickness and weight.

The researchers developed a material that is so thin it is almost two-dimensional, with characteristics that manipulate and enhance properties of the waveguide. They developed and tested two conformal coatings, one for guiding the signal and one to cloak the waveguide. They created the coatings by judiciously engineering the patterning on the surfaces to enable new and transformative waveguide functionality.

This quasi two-dimensional conformal coating that is configured as a cloaking material can solve the crosstalk and blockage problem. Dielectric waveguides are not usually used singly, but in bundles. Unfortunately, conventional waveguides leak, allowing the signal from one waveguide to interfere with those located nearby.

Improving the properties of the waveguide to carefully control polarization and other attributes allows the waveguides to be smaller, and alleviating crosstalk allows these smaller waveguides to be more closely bundled. Smaller waveguides more closely bundled could lead to increased miniaturization.