Off-axis parabolic mirror:separate focus

An off-axis parabolic reflector is a surface reflector whose reflective surface is an intercepted portion of the parent parabolic.Off-axis parabolic mirrors can be used to focus parallel beams or collimated point sources without dispersion, and their off-axis design can separate the focus from the optical path.When the collimated beam is incident vertically at the bottom of the mirror base, the reflected light will converge at the focal point.A collimated beam can be obtained by placing a point light source at the focal point.
The Angle between the focused beam and the collimated beam is called the off-axis Angle.The off-axis parabolic mirrors with different off-axis angles can be obtained by intercepting different sections of the parent paraboloid.

Using the off-axis parabolic as the mirror surface can not only deflect the direction of the optical path, but also realize various beam collection, beam collimation and beam focusing.This design has the following advantages:
Its off-axis design allows the focus to be separated from the rest of the optical path.

Compared with a lens, the use of off-axis parabolic mirrors does not produce spherical aberration, chromatic aberration, and does not introduce phase delay and absorption loss.