Marwan AbuLeil | Ben Gurion University of the Negev (original) (raw)

Papers by Marwan AbuLeil

Optics & laser technology/Optics and Laser Technology, Dec 1, 2024

Journal of Biomedical Optics, Sep 8, 2023

Social Science Research Network, 2022

Laser & Photonics Reviews

Nanophotonics

Photonic metamaterials combined with liquid crystals (LCs) for tunability is a great niche for bu... more Photonic metamaterials combined with liquid crystals (LCs) for tunability is a great niche for building miniature devices with high performance such as fast flat tunable lenses, tunable filters, and waveplates. Sub-wavelength or nano-grating surfaces are homogenized to uniaxial waveplates with negative birefringence of unique dispersion when the period is less than the wavelength by at least a few times. This uniaxial metasurface, combined with the LC layer, is shown to act as a tunable retardation achromatic waveplate with 8 μm thick LC layer operating over wide spectral and angular ranges, as compared to using two nematic liquid crystal (NLC) retarders of thicknesses on the order of 30–60 μm, when no metasurface is used. Hence the device becomes miniature and 50× faster due to the thinner liquid crystal layer. The silicon nano-grating of 351 nm pitch and 0.282 fill factor is designed and fabricated to operate in the short-wave infrared range (SWIR). Switching between three achroma...

Biosensors

Ellipsometric Surface Plasmon Resonance (SPR) sensors are known for their relatively simple optic... more Ellipsometric Surface Plasmon Resonance (SPR) sensors are known for their relatively simple optical configuration compared to interferometric and optical heterodyne phase interrogation techniques. However, most of the previously explored ellipsometric SPR sensors based on intensity measurements are limited by their real-time applications because phase or polarization shifts are conducted serially. Here we present an ellipsometric SPR sensor based on a Kretschmann–Raether (KR) diverging beam configuration and a pixelated microgrid polarization camera. The proposed methodology has the advantage of real-time and higher precision sensing applications. The short-term stability of the measurement using the ellipsometric parameters tanψ and cos(Δ) is found to be superior over direct SPR or intensity measurements, particularly with fluctuating sources such as laser diodes. Refractive index and dynamic change measurements in real-time are presented together with Bovine Serum Albumin (BSA)–an...

Single pixel liquid Crystal (SPLC) layer combined with light responsive material such as semicond... more Single pixel liquid Crystal (SPLC) layer combined with light responsive material such as semiconductor form what is called optically addressed spatial light modulator which is used for optical computing and image conversion. When LCs are part of a resonant photonic structure the optical readout can be made of narrow optical signatures and the strong electro/thermooptic effects in the LC reveal strong variations of the readout signal. Motivated by this approach several modes examined to demonstrate SPLC infrared/thermal camera using IR photosensors, VO2 bolometric layer, porous Si, and graphite as thermal absorption layer. Semiconductor photosensors gave the best performance until now.

IEEE Photonics Technology Letters, 2020

Wavelength dependence of phase modulators has been one of the main challenges in spectroscopic el... more Wavelength dependence of phase modulators has been one of the main challenges in spectroscopic ellipsometry/polarimetry (EP) which significantly complicates signals analysis. A known approach to overcome this complication is using rotatable polarizers. However, the use of rotatable polarizers induces mechanical vibrations and unnecessary errors to the system. In this work, a novel spectroscopic configuration to extract the spectral changes of the EP parameters applied to surface plasmon resonance (SPR) sensing is presented. The setup utilizes the integration of a recently developed achromatic variable liquid crystal waveplate to the SPR in Kretschmann-Raether configuration and using three phase shifts to extract the EP parameters of the SPR sample.

Scientific Reports, 2020

In this paper, we present a new hyperspectral compact camera which is designed to have high spati... more In this paper, we present a new hyperspectral compact camera which is designed to have high spatial and spectral resolutions, to be vibrations tolerant, and to achieve state-of-the-art high optical throughput values compared to existing nanosatellite hyperspectral imaging payloads with space heritage. These properties make it perfect for airborne and spaceborne remote sensing tasks. The camera has both hyperspectral and panchromatic imaging capabilities, achieved by employing a wedge-shaped liquid crystal cell together with computational image processing. The hyperspectral images are acquired through passive along-track spatial scanning when no voltage is applied to the cell, and the panchromatic images are quickly acquired in a single snapshot at a high signal-to-noise ratio when the cell is voltage driven.

Scientific Reports, 2016

Spectroscopic imaging has been proved to be an effective tool for many applications in a variety ... more Spectroscopic imaging has been proved to be an effective tool for many applications in a variety of fields, such as biology, medicine, agriculture, remote sensing and industrial process inspection. However, due to the demand for high spectral and spatial resolution it became extremely challenging to design and implement such systems in a miniaturized and cost effective manner. Using a Compressive Sensing (CS) setup based on a single variable Liquid Crystal (LC) retarder and a sensor array, we present an innovative Miniature Ultra-Spectral Imaging (MUSI) system. The LC retarder acts as a compact wide band spectral modulator. Within the framework of CS, a sequence of spectrally modulated images is used to recover ultra-spectral image cubes. Using the presented compressive MUSI system, we demonstrate the reconstruction of gigapixel spatio-spectral image cubes from spectral scanning shots numbering an order of magnitude less than would be required using conventional systems.

SPIE Proceedings, 2014

ABSTRACT Following the mature liquid crystals (LCs) display technology, there is a significant in... more ABSTRACT Following the mature liquid crystals (LCs) display technology, there is a significant interest in implementing these devices into other non-display applications. Hence the emerging field of LC photonics is becoming increasingly active in which the strong electrooptic properties of LCs are harnessed for these applications particularly for imaging such as the use of SLMs, tunable focus lenses, tunable filters and polarization control devices. In this paper we review our recently developed LC devices integrated into full field optical coherence tomography system, into multi-spectral skin diagnosis system and in extended depth of focus imaging system.

Optics Express, 2019

An ellipso-polarimetric camera integrated with improved field of view tunable achromatic waveplat... more An ellipso-polarimetric camera integrated with improved field of view tunable achromatic waveplate (AWP) over wide spectral band based on nematic liquid crystal retarders is presented. The AWP operates as half, quarter and full waveplate over a wide range of 430-780nm and wide field of view. The proposed analysis proved that capturing images at these modes is sufficient to extract the ellipsometric parameters: sin(2ψ), cos(Δ) and the Stokes parameters S1 and S3, besides showing the relations in between. Transmission and reflection modes setups are demonstrated in addition to an ellipso-polarimetric smartphone camera. The results show for the first time superiority of cos(Δ) images in which prominent contrast and fine details appear even with scattering objects and higher immunity to device errors. Biometric, remote sensing and archeological improved imaging applications are demonstrated.

We developed a novel spectral microscopy imaging method that opens the path towards automated can... more We developed a novel spectral microscopy imaging method that opens the path towards automated cancer detection in biopsies. By using the advanced compressive sensing framework, we are able to capture spectral images with unprecedented resolution and speed. We tested the performance of our compressive hyperspectral imaging system for histopathology of cancer cells and have been able to demonstrate unprecedented high detection accuracy. Our method is based on a commercial microscope, it is modular and versatile, and can be used for other applications that require rapid acquisition of high quality spectral images.

Sensors

Resonant-based sensors are attractive optical structures due to the easy detection of shifts in t... more Resonant-based sensors are attractive optical structures due to the easy detection of shifts in the resonance location in response to variations in the analyte refractive index (RI) in comparison to non-resonant-based sensors. In particular, due to the rapid progress of nanostructures fabrication methods, the manufacturing of subwavelength and nano-scale gratings in a large area and at a low cost has become possible. A comparative study is presented involving analysis and experimental work on several subwavelength and nanograting structures, highlighting their nano-scale features’ high potential in biosensing applications, namely: (i) Thin dielectric grating on top of thin metal film (TDGTMF), which can support the excitation of extended surface plasmons (ESPs), guided mode resonance, or leaky mode; (ii) reflecting grating for conventional ESP resonance (ESPR) and cavity modes (CMs) excitation; (iii) thick dielectric resonant subwavelength grating exhibiting guided mode resonance (G...

Liquid Crystals XVIII, 2014

Following the mature liquid crystals (LCs) display technology, there is a significant interest in... more Following the mature liquid crystals (LCs) display technology, there is a significant interest in implementing these devices into other non-display applications. Hence the emerging field of LC photonics is becoming increasingly active in which the strong electrooptic properties of LCs are harnessed for these applications particularly for imaging such as the use of SLMs, tunable focus lenses, tunable filters and polarization control devices. In this paper we review our recently developed LC devices integrated into full field optical coherence tomography system, into multi-spectral skin diagnosis system and in extended depth of focus imaging system.

Materials

Extraction of spectral information using liquid crystal (LC) retarders has recently become a topi... more Extraction of spectral information using liquid crystal (LC) retarders has recently become a topic of great interest because of its importance for creating hyper- and multispectral images in a compact and inexpensive way. However, this method of hyperspectral imaging requires thick LC-layer retarders (50 µm–100 µm and above) to obtain spectral modulation signals for reliable signal reconstruction. This makes the device extremely slow in the case of nematic LCs (NLCs), since the response time of NLCs increases proportionally to the square of the LC-layer thickness, which excludes fast dynamic processes monitoring. In this paper, we explore two approaches for solving the speed problem: the first is based on the use of faster nanospiral ferroelectric liquid crystals as an alternative to NLCs, and the second is based on using a passive multiband filter and focuses on multispectral extraction rather than hyperspectral. A detailed comparative study of nematic and ferroelectric devices is ...

Optics Letters, 2016

Multispectral tunable filters with high performance are desirable components in various biomedica... more Multispectral tunable filters with high performance are desirable components in various biomedical and industrial applications. In this Letter, we present a new narrowband multispectral tunable filter with high throughput over a wide dynamic range. It is composed from a wideband large dynamic range liquid crystal tunable filter combined with a multiple narrowbands spectral filter made of two stacks of photonic crystals and cavity layer in between. The filter tunes between nine spectral bands covering the range 450-1000 nm with bandwidth &amp;amp;amp;amp;amp;amp;amp;lt;10 nm and throughput &amp;amp;amp;amp;amp;amp;amp;gt;80%.