Synthetic wave interference nano surface tri-dimensional on-line measuring system and method

Abstract

The invention relates to a nano-surface interference 3D online measurement method with composite wave and by light scanning and the system thereof. The range depends on the wavelength of the composite wave, and the system has a common path interference structure. The beam with spectral width of 40 nm is color dispersed into two sectored lights with wavelength continuously and uniformly distributed in space by a grating, the two sectored lights are collimated to two parallel lights with transverse misplacement and partial overlapping, and the overlapped part forms a composite wave. The parallel lights of the composite wave passes through a plano-convex focusing lens with a cylindrical surface coated with a semi-transmitting and reflective film, then one half of the lights are reflected to become reference light and the other half of the lights are focused to become light, and then the light is reflected by different measuring points, interfered with the reference light and detected by an array CCD. If the phase variation of the interference signal of each pixel of CCD is measured, then the longitudinal variation at the measuring point can be obtained. The nano-surface 2D measurement is finished by once location; and the nano-surface 3D measurement is finished by transverse scanning of light. The measurement range is 600-1,000 micron, and the resolution is higher than 5 nm. The invention has the advantages of high measurement speed, and low cost; and is suitable for measurement of nano-surface with boss and deep groove.

Description

technical field [0001] The invention relates to a synthetic wave interference nanometer surface three-dimensional online measurement method and system using light scanning, in particular to a nanometer surface three-dimensional online measurement method and system with a boss and deep groove structure, belonging to the field of optical measurement technology . Background technique [0002] [1] D.P. Hand, T.A. Carolan, J.S. Barton, and J.D.C. Jones, Optics Letters, 1993, Vol. 18, No. 16, pp. 1361-1363. The working principle of the prior art document [1] is shown in Figure 1. The light emitted by the semiconductor laser passes through the Faraday isolator and the optical fiber 50:50 coupler, and then reaches the measuring head. The measuring head is a Fizeau interferometer, and a part of the light is The reflection of the end face of the fiber is used as the reference light, and the other part of the light is projected onto the measured surface after being focused by the self...

AI Technical Summary

Problems solved by technology

[0008] 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;

[0009] 2. It is sensitive to interference such as measurement environment vibration and temperature drift, and is not suitable for online measurement;

[0010] 3. The measurement range is limited by the wavelength λ of the incident light wave, the measurement range is less than λ / 2, and it is impossible to measure the nano-surface with the boss and deep groove structure

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