1. Automatic focus control: the astigmatic lens approach;Cohen;Appl. Opt.,1984
2. Astigmatic defocus sensor: its performance and optimization;Konwar;J. Opt.,2024
3. Direct defocus measurement using single astigmatic lens: a theoretical study;Konwar,2023
4. Development of the fast astigmatic auto-focus microscope system;Hsu;Meas. Sci. Technol.,2009
5. Sensor for dynamic focus control of a deformable mirror;Kazasidis;Appl. Opt.,2020