Sub-diffraction-limit light sheet enabled by a super-oscillatory lens with an enlarged field of view and depth of focus.

Static light sheets are widely used in various super-resolution three-dimensional (3D) imaging applications. Here, a multifocal diffraction-free optimized design method is proposed for super-oscillatory lenses (SOLs) owning an enlarged field of view (FOV) to generate sub-diffraction-limit light sheets with reduced divergence. Various propagation lengths of sub-diffraction-limit thickness for light sheets can be obtained by adopting corresponding numbers of discrete foci and spacing between them. In particular, the propagation lengths of 150.4λ and 118.9λ are obtained by SOLs with an enlarged FOV of 150λ and 820λ, respectively, which show the longest depth of focus (DOF), as far as we know, and are the first to realize the combination of enlarged DOF and FOV for SOLs. We show a way of using binary-amplitude modulation to generate static light sheets with sub-diffraction-limit thickness and reduced divergence, which is simple, easy to integrate, and sidelobe-suppressed.