Tunable edge enhancement by higher-order spiral Fresnel incoherent correlation holography system
Yuanzhuang Bu, Xi Wang, Yu Li, Yanli Du, Qiaoxia Gong, Guangchao Zheng, Fengying Ma
Abstract
Abstract Tunable edge enhancement can selectively emphasize the edge features of objects. We demonstrate a higher-order spiral Fresnel incoherent correlation holography system to realize isotropic edge enhancement with tunable width. The spatial light modulator is space-division multiplexed by a conventional lens and a spiral lens with a series of higher-order Laguerre–Gaussian phases. The effects of the radial quantum number p and the angular quantum number l on the spatial filtering are theoretically discussed, as well as confirmed by simulations and experiments. Reconstruction images of resolution target, hairs and label-free onion cells all show obvious tunable edge enhancement effects, which makes the edge information easier to be identified. Furthermore, double-edge enhancement is also detected for the first time.