US Patent 7453619 Rotary optical delay line

Disclosed herein is an optical delay line. The optical delay line includes a body and at least one wing, which constitute a rotating body that rotates around a rotational axis. The rotational wing includes a retroreflective curved surface, which is formed so that light can be vertically reflected by a reflective surface of the rotational wing. The retroreflective curved surface is formed so as to reversely reflect the light while varying an optical path difference at a predetermined speed when the rotating body rotates at a regular angular velocity. Thus, a long time delay value can be effectively generated.