Measurement of Lubricant Film Thickness Using Spectral Domain Optical Coherence Tomography (SD-OCT)
Y-W. Qin, H. Zhao and L. Zhang
A thermal-light source spectral domain optical coherence tomography (SD-OCT) was introduced to measure lubricant film thickness. An efficient interference spectrum decoupling algorithm was used to improve the signal-to-noise ratio and image contrast by eliminating both the direct current (DC) and the autocorrelation noise. Then high quality one-dimensional (1-D) depth and two-dimensional (2-D) image of the film were obtained with the proposed method. The film thickness was measured from the obtained image. It was experimentally demonstrated that this method can achieve the accurate measurement of lubricant film thickness.
Keywords: Laser, lubricant, film thickness, optical coherence tomography (OCT), spectral domain optical coherence tomography (SD-OCT), cross-sectional image