Making Microlenses smaller than a human hair

3-Second Blueprint (English)

1. A fiber laser ablates micro-pit patterns into a silicon wafer, which HF and nitric acid isotropically etch into smooth bowls.
2. High-speed spin coating deposits a thin silicone resin film across the etched silicon mold until cured.
3. Demolding yields thousands of sub-hair-width polymer microlenses, with tuned etch profiles focusing light to spots or lines.