Su Rong, Kirillin Mikhail, Chang Ernest W, Sergeeva Ekaterina, Yun Seok H, Mattsson Lars
Opt Express. 2014 Jun 30;22(13):15804-19. doi: 10.1364/OE.22.015804.
Optical coherence tomography (OCT) is a promising tool for detecting micro channels, metal prints, defects and delaminations embedded in alumina and zirconia ceramic layers at hundreds of micrometers beneath surfaces. The effect of surface roughness and scattering of probing radiation within sample on OCT inspection is analyzed from the experimental and simulated OCT images of the ceramic samples with varying surface roughnesses and operating wavelengths. By Monte Carlo simulations of the OCT images in the mid-IR the optimal operating wavelength is found to be 4 µm for the alumina samples and 2 µm for the zirconia samples for achieving sufficient probing depth of about 1 mm. The effects of rough surfaces and dispersion on the detection of the embedded boundaries are discussed. Two types of image artefacts are found in OCT images due to multiple reflections between neighboring boundaries and inhomogeneity of refractive index.
光学相干断层扫描（OCT）是一种很有前景的工具，可用于检测氧化铝和氧化锆陶瓷层中表面以下数百微米处的微通道、金属印记、缺陷和分层。通过对具有不同表面粗糙度和工作波长的陶瓷样品的实验和模拟OCT图像，分析了样品表面粗糙度和探测辐射在样品内的散射对OCT检测的影响。通过对中红外OCT图像的蒙特卡罗模拟，发现对于氧化铝样品，最佳工作波长为4 µm，对于氧化锆样品，最佳工作波长为2 µm，以实现约1 mm的足够探测深度。讨论了粗糙表面和色散对嵌入边界检测的影响。由于相邻边界之间的多次反射和折射率的不均匀性，在OCT图像中发现了两种类型的图像伪影。
