title: Flexible depth-of-field imaging system using a spatial light modulator.
abstract: A major problem of optical microscopes is their small depth-of-field (DOF), which hinders automation of micro object manipulation using visual feedback. Wavefront coding, a well-known method for extending DOF, is not suitable for direct application to micro object manipulation systems based on visual feedback owing to its expensive computational cost and due to a trade-off between the DOF and the image resolution properties. To solve such inherent problems, a flexible DOF imaging system using a spatial light modulator in the pupil plane is proposed. Especially, the trade-off relationship is quantitatively analyzed by experiments. Experimental results show that, for low criterion resolution, the DOF increases as the strength of the mask increases, while such a trend was not found for high criterion resolution. With high criterion resolution, the DOF decreases as the mask strength increases when high-resolution images are required. The results obtained can be used effectively to find the optimum mask strength given the desired image resolution.
authors: Department of Mechanical Engineering, Korea Advanced Institute of Science and Technology, Daejeon, South Korea. hscho@lca.kaist.ac.kr
authors: Deokhwa
authors: D
authors: Hong
authors: Kangmin
authors: K
authors: Park
authors: Hyungsuck
authors: H
authors: Cho
authors: Minyoung
authors: M
authors: Kim