arXiv subjects

Shaban B. Sulejman

Publications and source records attributed to Shaban B. Sulejman.

4 recordsLinked to original sources

arXiv2026

Wavelength and Polarization Multiplexed Nonlocal Metasurface for Quantitative Phase Microscopy

Imaging transparent samples remains an ongoing challenge in the study of unstained biological cells and material samples. Widely used methods trade off system complexity, cost and bulk, computational efficiency and information content. Here we demonstrate the use of a nonlocal metasurface located in the object plane for obtaining single-shot, low-noise differential phase contrast images visualising phase gradients along orthogonal directions in a sample obtained at wavelengths of 613 nm and 656 nm. Furthermore, we show that these images are sufficient to calculate the quantitative phase introduced into the transmitted optical field by the sample. We find that the recovered phase of an optical field generated by a spatial light modulator is in good agreement with specified values. We also present information-rich differential phase contrast images of unstained HeLa cells with the recovered phase excursion values consistent with the literature. Our results demonstrate the potential for metasurfaces as a platform for extracting information from an optical field for use in next-generation compact imaging systems with applications in medical diagnostics, biotechnology, and materials science.

physics.optics↗

arXiv2024

Metasurfaces for infrared multi-modal microscopy: phase contrast and bright field

Different imaging modalities are used to extract the diverse information carried in an optical field. Two prominent modalities include bright field and phase contrast microscopy that can visualize the amplitude and phase features of a sample, respectively. However, capturing both of these images on the same camera typically requires interchanging optical components. Metasurfaces are ultra-thin nanostructures that can merge both of these operations into a single miniaturized device. Here, a silicon-based metasurface that supports a Mie resonance is demonstrated to perform near-infrared phase contrast and bright field multi-modal microscopy that can be tuned by changing the polarization of the illumination. We performed experiments using optical fields with phase variations synthesized by a spatial light modulator and introduced by propagation through semi-transparent samples, including C. elegans, unstained human prostate cancer cells and breast tissue. The results demonstrate the potential of metasurfaces for label-free point-of-care testing.

physics.optics↗

arXiv2023

Reconfigurable Image Processing Metasurfaces with Phase-Change Materials

Optical metasurfaces have been enabling reduced footprint and power consumption, as well as faster speeds, in the context of analog computing and image processing. While various image processing and optical computing functionalities have been recently demonstrated using metasurfaces, most of the considered devices are static and lack reconfigurability. Yet, the ability to dynamically reconfigure processing operations is key for metasurfaces to be able to compete with practical computing systems. Here, we demonstrate a passive edge-detection metasurface operating in the near-infrared regime whose image processing response can be drastically modified by temperature variations smaller than 10° C around a CMOS-compatible temperature of 65° C. Such reconfigurability is achieved by leveraging the insulator-to-metal phase transition of a thin buried layer of vanadium dioxide which, in turn, strongly alters the nonlocal response of the metasurface. Importantly, this reconfigurability is accompanied by performance metrics - such as high numerical aperture, high efficiency, isotropy, and polarization-independence - close to optimal, and it is combined with a simple geometry compatible with large-scale manufacturing. Our work paves the way to a new generation of ultra-compact, tunable, passive devices for all-optical computation, with potential applications in augmented reality, remote sensing and bio-medical imaging.

physics.optics↗

arXiv2022

Thin film notch filters as platforms for biological image processing

Many image processing operations involve the modification of the spatial frequency content of images. Here we demonstrate object-plane spatial frequency filtering utilizing the angular sensitivity of a commercial spectral bandstop filter. This approach to all-optical image processing is shown to generate real-time pseudo-3D images of transparent biological and other samples, such as human cervical cancer cells. This work demonstrates the potential of non-local, non-interferometric approaches to image processing for uses in label-free biological cell imaging and dynamical monitoring.

physics.optics↗