Research On Measurement Of Surfaces' Roughness Using Optically Common-path And Polarized System

With the development of scientific technique and the advent of "information times", there is an increasing demand on the quality of the precisely processed surfaces by the mechanics, electronics and optics in the recent years. Therefore, more advanced measurement means is demanded to achieve higher processed surfaces' quality.By summarizing the methods to measuring the surfaces' roughness that have already existed, and analyzing the advantage and the disadvantage of their principle. A new measurement method of non-contact surface roughness is developed in this paper. It is based on common-path, optical polarized and interferometer measurement system, not requiring additional reference surface. It's working principle and measurement uncertainty is analyzed and proved, employing Jones matrix on the basis of wave optics. A standard sample whose Ra is 0.012 um is surveyed on this principle, and the measuring curve is simulated, and the roughness value is caculated, verifying systematic feasibility. It has a good ability to resist the disturbance from vibration outside the apparatus. It has simple constructor and high measuring sensitivity.