A cube-corner prism is also known as a reflector that reflects the image or beam backward to the original direction by three reflections. Even if the Angle of incidence is not zero, the beam or image will invert and reflect 180°. These reflectors are not affected by alignment and are ideal for backward-reflecting optical components. For these pyramid prisms, the parallelism tolerance of incident light and reflected light is within 3 arcsec. However, the incident light does not overlap with the reflected light, but is offset by a certain distance, unless the incident light hits the center of the reflector. For example, if the incident light incident point is 3 mm to the right of the center of the prism, then the reflected light will exit 3 mm to the left of the center. The maximum beam diameter that a prism can reflect is listed in the table below. 

In addition, when the reflected light passes through a solid corner cone prism, the polarization state also changes.