Concave Mirrors with Hole

Concave mirrors with hole (also called perforated concave mirrors) are specialized optical components that combine two critical functions: the focusing/reflecting properties of concave mirrors and an integrated through-hole (aperture) for beam injection or extraction. This dual functionality makes them ideal for multi-pass optical systems like Herriott cells (used for gas sensing) and folded laser cavities, where beams need to enter/exit the system without blocking the reflective surface.