Roughness measurement of metals using a modified binary speckle image and adaptive optics

摘要: Abstract This paper proposes an integrated roughness measurement system that is based on adaptive optics (AO) and binary analysis of speckle pattern images. The aim this study was to demonstrate the necessity for AO compensation in regions containing both heat fluid flow turbulences. A image obtained by projecting a laser beam onto specimen surface, reflected from surface binarized experimentally correlate intensity with roughness. In absence correction scheme, induced turbulences can severely increase residual rms error 0.14 1.4 μm. After real-time closed-loop correction, we reduce wavefront root mean square (rms) 0.12 μm, which not only compensates aberration disturbances but also improves overall performance optical system. addition, having different gains investigated, threshold gain value found be able steadily compensate errors less than 2 s. Measurement results five steel samples ranging 0.2 3.125 μm (0.3λ 5λ, where λ diode wavelength) excellent correlation between distribution images average coefficient 0.9982. Furthermore, proposed AO-assisted good agreement stylus method 9.73% values consistently obtained.