OFF-AXIS ALIGNMENT SYSTEM AND ALIGNMENT METHOD

摘要

Disclosed is an off-axis alignment system, which comprises a lighting module (10), an interference module (20) and a detection module (30) in sequence in accordance with a beam propagation path, wherein the interference module (20) comprises: a polarizing beam splitter (21) having four side surfaces, both the lighting module (10) and the detection module (30) being located at the first side of the polarization beam splitter (21); a first 1/4 wave plate (22) and a first reflector (23) which are located at the second side opposite to the first side in sequence; and a second 1/4 wave plate (24), a pyramid prism (25) and a third 1/4 wave plate (26), and a second reflector (27) and a lens (28) which are respectively provided at the other two sides of the polarization beam splitter (21), the second reflector (27) being located on back focal plane of the lens (28), the bottom surface centre of the pyramid prism (25) being located on an optical axis of the lens (28). Also disclosed is an off-axis alignment method.