Off-Axis Parabolic Mirror is the first surface mirror, the reflective surface is segment of a parent paraboloid. It can focus a collimated beam or collimate a divergent source. The off-axis design makes the focal point to be separated from the optical path. Using Off-Axis Parabolic Mirror does not produce spherical aberration, color aberration, and eliminates the phase delay and absorption loss introduced by the transmissive optics.