When a laser beam modifies a material, those modifications can either be temporary or permanent, and the change can also be either extremely subtle or drastic. In any case, once such a modification has taken place, the modified material starts responding differently to the laser beam.
This interaction between the laser beam and the modified materials is typically overlooked or even actively prevented because it’s viewed as an undesired artifact. However, researchers at Bilkent University and Middle East Technical University (both in Ankara, Turkey) have taken advantage of these interactions to create structures within silicon that enable photonic devices.
In research described in the journal Nature Photonics, the Turkey-based researchers have developed a 3D laser fabrication technique that deliberately creates the conditions for exploiting these interactions, known as nonlinear feedback mechanisms. The researchers have dubbed the resulting structures inside of the silicon “in-chip” devices that they believe can serve in a host of applications. Among the predicted uses: silicon-based photonics components for near- and mid-IR photonics.