Broadband coherent modulation imaging with no knowledge of the illumination spectrum distribution: publisher's note.

This publisher's note contains a correction to Opt. Lett.48, 3977 (2023)10.1364/OL.495706.

Broadband coherent modulation imaging with no knowledge of the illumination spectrum distribution.

Coherent diffraction imaging (CDI) is an alternative way to achieve high-performance imaging without high-quality imaging lenses. Coherent modulation imaging (CMI) improves CDI's algorithmic convergence and applicability to general samples. A high degree of coherence of the source is essential for CDI, which limits its application to ultrafast pulsed sources with an intrinsically broad spectrum. Here, we propose an algorithm to increase the tolerance of CMI to low temporal coherence that tandemly employs the Wiener and Lucy deconvolution approaches. Simulations and visible light experiments demonstrate the effectiveness of our method. This work could pave the way for implementing CMI with attosecond pulsed lasers, laboratory x-ray sources, or electron microscopes.

Super-resolution near-field ptychography.

Compared to far-field ptychography, near-field ptychography can reduce the requirement on the detector dynamic range, while it is able to cover a larger field of view with a fewer number of sample scans. However, its spatial resolution is limited by the detector pixel size. Here, we utilize a pixel-super-resolved approach to overcome this limitation. The method has been applied to four types of experiment configurations using planar and divergent illuminations together with two different cameras with highly contrast specifications. The proposed method works effectively for up-sampling up to 6 times. Meanwhile, it can achieve ∼5.9-fold and ∼3.1-fold resolution improvement over the 6.5-µm and 2.4-µm detector pixel size. We also demonstrate the precisely quantitative phase imaging capability of the method by using a phase resolution target. The presented method is believed to have great potential in X-ray tomography and on-chip flow cytometry.

Reconstruction method of a ptychographic dataset with unknown positions.

Wavefield drift or wobbling occurs quite often in coherent scanning systems such as satellite laser communication, laser pointing of high-power lasers, or microscopy. The uncertainty of wavefront positions might result in blurred images or large measurement errors. Here we propose an iterative approach that can retrieve both the drift positions and complex-valued distribution of the wavefield from a ptychographic diffraction intensity dataset. We demonstrate the feasibility and effectiveness of the method in numerical simulation and an optical experiment. The method requires little a priori knowledge and thus would open up new opportunities in many fields.