Multiplanar imaging properties of Theon sieves

Abstract

Greek ladders with diffraction-limited array foci provide a probability to realize array imaging with equal intensity. Here, taking the ancient Theon sequence as an example, we design the optical structure and have measured the focusing properties by digital holography. Then, we verify the multiplanar imaging with different magnifications by experiment. The experimental results agree well with the theoretical analysis. In addition, bi-Fourier planes filtering technology is proposed to solve the problem of crosstalk between different imaging planes to further improve the imaging resolution. Therefore, we can freely design the focal length of the bifocal lens to achieve high-quality imaging at different resolutions. As a kind of amplitude-only diffractive lens, multifocal imaging provides a possibility of application in array biological imaging, ophthalmology, and an optical zoom system.

Phase-shifting digital holography with a tri-focal Fibonacci telescope in a single exposure

“…Based on previous work [24][25][26], a tri-focal sieve was fabricated with a diameter of 8.93 mm and three focal lengths of 75.0 mm, 90.0 mm and 112.5 mm, in which there were about 154 000 transparent pinholes. Figure 2 shows the optical path of the tri-focal photon-sieve telescope.…”

Multiplanar Fourier-transform phase-shifting digital holography with a generalized Fibonacci lens

“…Compared to traditional holography, Fourier holography records the spatial frequency spectrum of the object, which can be realized via the focusing lens or lens-less Fourier recording method. Based on previous work on photon sieves [16][17][18], here we introduce the generalized Fibonacci lens into phase-shifting digital holography. As is different from traditional photon sieves [19][20][21][22], the Fibonacci photon sieves can generate more than one focus on the optical axis, showing that it can provide multiplanar Fourier-transform operation.…”