Plane surface shape measurement method of optical fiber point-diffraction phase-shifting interferometer

Abstract

The invention discloses a plane surface shape measurement method of an optical fiber point-diffraction phase-shifting interferometer, belonging to the technical field of optical measurement. The method comprises the following steps: firstly the spherical wave diffracted by a measuring fiber is reflected by a plane mirror to be measured, is focused on the slant end surface of a reference fiber by an auxiliary positive lens, is reflected again to combine with the spherical wave diffracted by the reference fiber and perform interference, the obtained interference pattern is analyzed and processed by the standard method to obtain the aberration caused by the plane mirror to be measured and the auxiliary positive lens; secondly, the plane mirror to be measured is removed, the end surface of the measuring fiber is moved to the conjugate position of the plane mirror to be measured, the spherical waves diffracted by the measuring fiber and the reference fiber are combined to interfere again; the aberration caused by the auxiliary positive lens is obtained through the measurement of the step; and the measurement result of the first step minus that of the second step is the aberration caused by the plane mirror to be measured, and the aberration is corrected according to the incident angle of the spherical wave to obtain the surface shape of the plane mirror to be measured. The method of the invention can be used to effectively increase the measurement precision of the plane surface shape of the optical fiber point-diffraction phase-shifting interferometer.

Description

technical field [0001] The invention belongs to the technical field of optical precision measurement, and relates to a plane shape measurement method on an optical fiber point diffraction phase-shifting interferometer, which can realize full-scale high-precision measurement of an optical plane. Background technique [0002] Planar optical components are widely used in optical systems, and their flatness is usually below one wavelength. The flatness of planar components is generally measured by optical interference method, and a standard reference plane is required as the plane datum during measurement. The usual interferometer uses a standard plate manufactured by optical processing as a reference plane, and there is always a certain surface error, which limits the accuracy of the interferometer to measure the plane surface. The measurement accuracy of the current interferometer plane shape can only reach λ / 20~λ / 50 (λ is the wavelength of light, the value is 632.8nm), which...

AI Technical Summary

Problems solved by technology

[0011] The purpose of the present invention is to propose a new measurement method in order to overcome the defect that the use of a flat beam splitter leads to the introduction of large additional aberrations that affect the measurement accuracy in the existing optical fiber point diffraction plane shape measurement technology

Images