Substantial improvements in the nanofabrication and characteristics of gold Fresnel zone plates yielded unprecedented resolution levels in hard-x-ray microscopy. Tests performed on a variety of specimens with 8–10keV photons demonstrated a first-order lateral resolution below 40nm based on the Rayleigh criterion. Combined with the use of a phase contrast technique, this makes it possible to view features in the 30nm range; good-quality images can be obtained at video rate, down to 50ms∕frame. The important repercussions on materials science, nanotechnology, and the life sciences are discussed.

Optical microscopy is an essential tool for exploring the structures and activities of cells and tissues. To break the limit of resolution caused by diffraction, researchers have made continuous advances and innovations to improve the resolution of optical microscopy since the 1990s. These contributions, however, still make sub-10[Formula: see text]nm imaging an obstacle. Here, we name a series of technologies as modulated illumination localization microscopy (MILM), which makes ultra-high-resolution imaging practical. Besides, we review the recent progress since 2017 when MINFLUX was proposed and became the inspiration and foundation for the follow-up development of MILM. This review divides MILM into two types: point-scanning and wide-field. The schematics, principles and future research directions of MILM are discussed elaborately.

Three-dimensional structured illumination microscopy (3D-SIM) plays an essential role in biological volumetric imaging with the capabilities of improving lateral and axial resolution. However, the traditional linear 3D algorithm is sensitive to noise and generates artifacts, while the low temporal resolution hinders live-cell imaging. In this paper, we propose a novel 3D-SIM algorithm based on total variation (TV) and fast iterative shrinkage threshold algorithm (FISTA), termed TV-FISTA-SIM. Compared to conventional algorithms, TV-FISTA-SIM achieves higher reconstruction fidelity with the least artifacts, even when the signal-to-noise ratio (SNR) is as low as 5 dB, and a faster reconstruction rate. Through simulation, we have verified that TV-FISTA-SIM can effectively reduce the amount of required data with less deterioration. Moreover, we demonstrate TV-FISTA-SIM for high-quality multi-color 3D super-resolution imaging, which can be potentially applied to live-cell imaging applications.

A multi-image encryption with super-large-capacity is proposed by using spherical diffraction and filtering diffusion. In the proposed method, initial images are processed sequentially by filtering diffusion and chaos scrambling. The images are combined into one image using XOR operation. The combined image is encrypted by improved equal modulus decomposition after spherical diffraction. There are three main contributions of the proposed method—(1) resisting phase-retrieval attack due to the asymmetry of spherical diffraction; (2) high flexibility of decrypting images individually; and (3) super-large encryption capacity of the product of image resolution and grayscale level, which is the most significant advantage. The feasibility and effectiveness of the proposed encryption are verified by numerical simulation results.