Broadband Anti-Reflection Moth-Eye Structures Realized in the Above 1 THz Region by Laser Processing

We fabricate terahertz (THz) moth-eye antireflection (AR) structures on the surface of high-resistivity silicon via low-power femtosecond laser processing. We observed broadband AR performance at near-unity above 0.8 THz, where the upper value was measurement limited. Such values are unprecedented for laser fabricated samples, and shows the high potential of laser processing-based approaches for THz optics fabrication.