Absolute interference measurement method for plane shape of optical plane

The invention relates to an absolute interference measurement method for a plane shape of an optical plane, belonging to the technical field of the optical measurement. The method is as follows: firstly, spherical waves diffracted from a measuring fiber are reflected by a plane mirror to be detected, deflects and penetrates a plane beam splitter, are converged with spherical wavefront diffracted by a reference optical fiber and reflected by the plane beam splitter and the interference happens; an interference pattern is analyzed and processed by a standard method; and the optical aberration introduced by the plane mirror to be detected and the plane beam splitter is obtained in the first step. And then, the plane mirror to be detected is removed; the end face of the measuring optical fiber is moved to the conjugation position of the plane mirror to be detected; and the spherical waves diffracted from the measuring fiber and the reference optical fiber are converged and interference happens again; and the aber