Plane convex substrate lens for collimating high frequency electromagnetic rays, has static rough surface on side with convex profile, and antireflection coating layer that is provided on side with convex profile

摘要

The lens (1) has a static rough surface on a side with a convex profile, where the roughness depth and the lateral structural dimension of the surface correspond to quarter of terahertz-wavelength in lens material. An antireflection coating layer (5) is provided on the side with the convex profile. The lens is made of highly-pure silicon and has an aspheric form. The lens focuses terahertz-beam of rays in a focal point of a photo-conductive semiconductor antenna (2).