OP10 - Interference Measurement of Rough Surface Relief
- SENSOR+TEST Conferences 2009
2009-05-26 - 2009-05-28
Congress Center Nürnberg
- Proceedings OPTO 2009 & IRS² 2009
- OPTO Poster Session
- O. Angelsky, O. Maksimyak, P. Maksimyak - Chemivtsy University, Chemivtsy, Ukraine
- 161 - 166
The optical techniques are non-contact, non-destructive and highly efficient for diagnostics of rough surfaces. The optical techniques may be divided into profile interference and heterodyning techniques, techniques based on measuring of the angular distribution of scattered radiation3, and optical correlation techniques. High operation rates, data processing in the optical channel, high accuracy of measurements, feasibilities for real-time data processing, and small sizes of the measuring devices are the main advantages provided by optical correlation diagnostic methodology6. However, when the height of surface inhomogeneities exceeds the wavelength of the probing beam, and the specular component of the reflected radiation is absent, the unambiguous connection between the statistical parameters of the roughness and of the scattered field is lost. The new approaches of fractal and singular optics are consequently needed for diagnostics of such surfaces. At the same time, these approaches so far provided only classification of rough surfaces into random and fractal ones.
In this paper, we promote the optical correlation technique for determining the height distribution function for surfaces with large surface inhomogeneities (roughness) and for the reconstruction of the relief structure of such a surface based on the results of measuring and processing of the longitudinal coherence function for the scattered field. For diagnostics of surfaces with large inhomogeneities one often uses the techniques of speckle optics. In these cases, however, the statistics of the height distribution of the inhomogeneities influences the results of measurements, and the depth of roughness must not exceed 3 microns. Optimization of interference measurements and computer processing of them provide reconstruction of the relief of regular surfaces with resolution 0.5 nm.