HSIEN-SHUN LIAOHuang, Ya KangYa KangHuangSyu-Gu, Jian YuanJian YuanSyu-GuHwu, En TeEn TeHwu2023-06-072023-06-072022-08-0114248220https://scholars.lib.ntu.edu.tw/handle/123456789/631942An astigmatic optical profilometer with a commercial optical pickup head provides benefits, such as high resolution, compact size, and low cost. To eliminate artifacts caused by complex materials with different reflectances, a z-axis modulation mode is proposed to obtain quantitative surface morphology by measuring S curves on all image pixels. Moreover, the slope of the linear region in the S curve shows a positive relationship with the surface reflectance. However, the slope was calculated using an offline curve fitting method, which did not allow real-time reflectance imaging. Furthermore, quantitative reflectance data were unavailable because of the lack of calibration. In this study, we propose a novel method for real-time reflectance imaging by measuring the amplitude of a focus error signal (FES). The calibration results displayed a linear relationship between the FES amplitude and reflectance. The reflectance image of a grating sample with chrome patterns on a glass substrate demonstrates accurate reflectance measurements with a micrometer spatial resolution.enastigmatism | optical profilometer | reflectancejournal article10.3390/s22166242360160002-s2.0-85136695192WOS:000845437600001https://api.elsevier.com/content/abstract/scopus_id/85136695192