Beam-scanning interference type nano surface tri-dimensional on-line measuring system and method

Abstract

Interference type nano-surface three-dimensional online measurement system and method using light beam scanning with common path interference structure can suppress environmental disturbance, including a grating for dispersing a light beam with a spectrum of 40nm to the light with spatial continuous distributed wavelength which is collimated to be parallel light by a plane-cylinder lens coated with semitransparent half-reflective film, therefore a half of light is reflected back as reference light, while another part is focused to light beam with different wavelengths reflected back to the system by different detected points and then dispersed to the light with spatial continuous distributed wavelength after interference with the reference light, so as to be detected by linear CCD. Different pixel of the CCD detect interference signal with different wavelength, and obtain interference signal phase change of each pixel, namely obtain longitudinal value change of corresponding detected point. The two-dimensional surface measurement can be realized by one location, and the three-dimensional surface measurement can be realized by light horizontal scanning, thereby improving greatly the measurement speed, reducing costs, extending measuring range to 300 um with resolution superior than 0.1nm using optical path tracking.

Description

technical field [0001] The invention relates to a light-scanning interference-type nanometer surface three-dimensional measurement system and method, in particular to a nanometer surface three-dimensional measurement system suitable for on-line measurement, which belongs to the technical field of optical measurement. Background technique [0002] There are two existing documents close to this technology: [0003] [1] D.P.Hand, T.A.Carolan, J.S.Barton, and J.D.C.Jones. "Profile measurement of optically rough surfaces by fiber-optic interferomtry", Opt.Lett., Vol.18, No.16, 1993, P.1361-1363. (Optics Letters, Vol. 18, No. 16, P.1361-1363) [0004] The technical principle of literature [1] is as follows: figure 1 shown. [0005] The light emitted by the semiconductor laser passes through the Faraday isolator and the fiber 3dB-coupler, and then reaches the measuring head. The measuring head is a Fizeau interferometer. A part of the light is reflected by the end face of the fi...

AI Technical Summary

Problems solved by technology

[0015] 1. They are all point scanning measurement methods, the measurement speed is slow, two-dimensional scanning is required for three-dimensional surface measurement, the scanning mechanism is complicated, and the instrument cost is high;

[0016] 2. Sensitive to the interference of the measurement environment, it is not suitable for online measurement;

[0017] 3. The measurement range is limited by the incident light wavelength λ, and the measurement range is less than λ / 2

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