Corner Cube Prisms are designed to reflect any ray or beam entering the prism face, regardless of the orientation of the prism, back onto itself. A mirror will only do that at the normal incidence. As a result, corner cubes are ideal where precision alignment is difficult or time-consuming. Retroreflectors will function even at very large angles of incidence. Due to their complex shape, however, corner cubes can often be difficult to mount. http://www.edmundoptics.com/onlinecatalog/displayproduct.cfm?productID=2056
See Also
6.6 - Cube Corner Retroreflectors
Constructive Cubes
Corner Cube Prisms
Corner Cube Retro-Reflectors
Corner Cube Retroreflectors
Figure 2.1.5 - Russells Rings forming Spheres from Three Pairs of Reflecting Mirrors
Figure 6.11 - Cube Corner Reflectors Dissipating and Concentrating
Holographic Universe
Mirrors and Lens of Cosmic Cinema
Part 04 - Rotation on Three Planes
Part 06 - Formation of Cubes