LAUSR

Various optical instruments have been developed for three-dimensional (3D) surface topography, including the white light interference, reflectance confocal microscopes, and digital holographic microscopes, etc. However, the steep local slope of objects may cause the light to be reflected in a way that it will not be captured by the objective lens because of the finite collection angle of the objective. To solve this "shadow problem," we report a method to enlarge the collection angle range of optical sectioning structured illumination microscopy by capturing sectioned images of the objects from multiple angle of views. We develop a multi-view image fusion algorithm to reconstruct a single 3D image. Using this method, we detect previously invisible details whose slopes are beyond the collection angle of the objective. The proposed approach is useful for height map measurement and quantitative analyses in a variety of fields, such as biology, materials science, microelectronics, etc.