Breakthrough Crystal Lets Scientists “Write” Nanoscale Patterns With Light

Scientists found that arsenic trisulfide crystals can be permanently patterned with ordinary continuous-wave laser light.

The material shows a strong light-induced refractive index change, allowing nanoscale features such as an Einstein portrait and QR-code-like design.

Because the patterns are written directly into the crystal, the approach could simplify photonic component fabrication and avoid cleanroom processing.

Potential applications include sensors, imaging, optical authentication, anti-counterfeiting, and other light-driven devices.