8th Liquid Matter Conference September 6-10, 2011 Wien, Austria ...

Fri 911:10-14:00P6.33Thin film thickness measurement using colors ofinterference fringesSanaz Sadegh 11 Sharif University of Thechnology, Tehran-Azadi Av. ,Tehran, IranIntroductionThere are several methods for measuring thin film thickness, however, for the analysisof liquid film motors we need a method which is capable of measuring the thickness using asingle image of the film. In this work, we use the colors that appear on thin films, such as soupbubbles, which is a result of light interference to calculate the thickness of the layer. ExperimentalProceduresFor thin film thickness measurement from color of interference fringes we first haveto know the theoretical relation between color of reflected light and film thickness. To find thisrelation we notice that color vision is described as being trichromatic. So, we can calculate theRGB components of color for every thickness using the layer reflection intensity relations andcolor matching functions. Then we transform RGB color space to HSV color space because hue,H(t), will be a monotonic and reversible function of thickness, t. The final step is to find theunknown thickness using the measured hue from our film image.33