Papers by Ibrahim Abdulhalim
Optics & Photonics News, May 1, 2000
Journal of Physical Chemistry & Biophysics, Sep 11, 2019
This chapter presents several non-conventional silicon-based integrated circuits realizing optica... more This chapter presents several non-conventional silicon-based integrated circuits realizing optical modulators as well as other functionalities such as logic gates. Although the presented concepts are in the state of pure research and yet far from being industrially implemented, they show the potential as well as a different point of view of how to allocate existing resources for achieving the desired goal. It presents a nano-scale miniaturized waveguide Mach–Zehnder interferometer (MZI) realized on a silicon chip. By illuminating the MZI structure with visible light, one varies the silicon (Si) refraction index and consequently the Si absorption coefficient for an infra-red (IR) information beam passing through it. The visible light illumination is the control command that turns the modulator to its ON and OFF states. In our case, the structure is illuminated in a spatially non-uniform way, therefore breaking the symmetry or the balance between the two arms of the interferometer. The advantage of this approach is that it results in a high contrast, since when the arms are balanced, no output is obtained, whereas even the slightest imbalance will produce an output signal. Therefore, a very small-scale device can produce the desired outcome. This approach differs from the one in which external visible illumination is applied directly on the optical waveguide that guides the IR beam, where one needs a long interaction length to obtain a high contrast, because there is no balancing mechanism.
Proceedings of SPIE, Feb 9, 2006
ACS Applied Materials & Interfaces, Aug 25, 2020
Nanoscale, 2019
Vis-NIR light absorption and effective separation of electron–hole pairs are achieved by integrat... more Vis-NIR light absorption and effective separation of electron–hole pairs are achieved by integrating the SPR modes of plasmonic nanoparticle and film, which lead to an 88-fold increase in photocurrent under λ > 420 nm compared to TiO2.
Journal of biotechnology & biomaterials, Mar 19, 2018
Journal of materials chemistry. A, Materials for energy and sustainability, 2018
Following are the characterizations of multiple-morphology Au NPs and the inverted organic solar ... more Following are the characterizations of multiple-morphology Au NPs and the inverted organic solar cells with and without Au NPs arrays. A comparison table of non exhaustive survey of Au plasmonic enhanced OPVs with P3HT:PC61BM and PTB7:PC71BM blend systems is also presented in following.
Chemosensors, Nov 5, 2022
This article is an open access article distributed under the terms and conditions of the Creative... more This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY
Applied physics reviews, Sep 1, 2020
In this review, the weightiest decadal developments of surface-enhanced Raman scattering (SERS) a... more In this review, the weightiest decadal developments of surface-enhanced Raman scattering (SERS) and nanoplasmonic materials in sensing applications are discussed. Today, there are several well-established research directions where plasmonic detection is employed extensively, namely, food and water quality monitoring, viruses, pathogenic bacteria and hazardous toxin investigations for theranostic applications, and explosive substance detection for military and civil protection purposes. A combination of vibrational spectroscopy and surface nanoengineering has gained a reputation as a powerful weapon for rapid and accurate determination of submolecular quantities of nanoanalytes. Signal enhancement achieved by employing various metallic nanoparticles and nanostructures can be amplified significantly due to the electromagnetic field confinement effect. Localized surface plasmon waves, which are responsible for the phenomenon, promote light absorption at nanovolume, generating 'hot spots' with an incredibly intense and confined electromagnetic field close to the nanosculptured metallic surface. However, the formation of the hot spot network is heavily dependent on morphology, size, and spatial arrangement of plasmonic nanomaterials. Under optimal excitation conditions, the interaction between the optically induced electromagnetic field in the hot spot region and a probing analyte attached to the nanosculptured metallic substrate enlarges photon scattering cross section, increasing signal intensity by 10 6-10 10. As a result, fast single-molecule vibrational fingerprint recording is possible. This focused review collects recent state-of-the-art developments in nanoplasmonic SERS sensing, highlighting the most efficient surface morphology designs that hold the most promise for future developments.
HAL (Le Centre pour la Communication Scientifique Directe), Aug 23, 2020
We propose a novel implementation of autonomous photonic neural networks based on optically-addre... more We propose a novel implementation of autonomous photonic neural networks based on optically-addressed spatial light modulators (OASLMs). In our approach, the OASLM operates as a spatially non-uniform birefringent waveplate, the retardation of which nonlinearly depends on the incident light intensity. We develop a complete electrical and optical model of the device and investigate the optimal operational characteristics. We study both, feed-forward and recurrent neural networks and demonstrate that OASLMs are promising candidates for the implement of autonomous photonic neural networks with large numbers of neurons and ultra low energy consumption.
Enhancing the optical fields near metal nanostructures is of high importance for sensing, energy ... more Enhancing the optical fields near metal nanostructures is of high importance for sensing, energy harvesting and improving the efficiency of optoelectronic devices. Surface enhanced spectroscopies such as Raman scattering (SERS), fluorescence (SEF) and infrared absorption (SEIRA) are enhanced significantly thus allowing lower detection limit and suprresolved imaging. Solar energy harvesting can be improved by designing structures that enhance the local optical field over wide spectral and angular ranges covering the whole solar spectrum. Detectors for the short wave and mid-IR ranges with higher efficiencies started to appear following an optimum designs incorporating plasmonic nanostructures. During the last few years we have been investigating several plasmonic nanostructured thin films for improved biosensors and lately for energy harvesting devices using variety of configurations: standard Kretchmann-Raether configuration, grating coupling, free space excitation of localized plasmons (LSPs) from nanosculptured thin films, and lately excitation of LSPs via extended surface plasmons (ESPs). The later configuration was shown both theoretically and experimentally (using SEF and SERS) to reveal extraordinary enhancement when the matching conditions between the ESP and the LSP are met. Several configurations for improved SPR biosensors and ultrahigh enhancement of local optical fields will be presented with the potential applications in sensing, solar energy harvesting and optoelectronic devices. Acknowledgments: This research was conducted partially by NTU-HUJ-BGU Nanomaterials for Energy and Water Management Programme under the Campus for Research Excellence and Technological Enterprise (CREATE), that is supported by the National Research Foundation, Prime Minister’s Office, Singapore. References 1. Atef Shalabney, C. Khare, Jens Bauer, B. Rauschenbach, and I. Abdulhalim, J. Nanophoton. 6 (1), 061605 (2012). 2. Alina Karabchevsky, Chinmay Khare, Bernd Rauschenbach, and I. Abdulhalim, J. NanoPhotonics 6, 061508-1, 12pp (2012). 3. I. Abdulhalim, Small 10, 3499-3514 (2014). 4. S.K. Srivastava, A. Shalabney, I. Khalaila, C. Gruner, B. Rauschenbach, and I. Abdulhalim, Small 10, 3579-3587 (2014). 5. Sachin K. Srivastava, H. Ben Hamo, A. Kushmaro, R. S. Marks, C. Gruner, B. Rauschenbach and I. Abdulhalim, Analyst, 140, 3201-3209 (2015). 6. Sachin K. Srivastava, C. Gruner, D. Hirsch, B. Rauschenbach, and I. Abdulhalim, Opt. Exp., Accepted (2017). 7. Anran Li, Sivan Isaacs, Ibrahim Abdulhalim, Shuzhou Li, J. Phys. Chem. C 119, 19382-9 (2015). 8. Anran Li, Sachin Srivastava, Ibrahim Abdulhalim, Shuzhou Li, Nanoscale 8, 15658-664 (2016). 9. Sachin K. Srivastava, Anran Li, Shuzhou Li, Ibrahim Abdulhalim, J. Phys. Chem. C 120, 28735-42 (2016).
In Full field Optical Coherence Tomography (FFOCT) lateral resolution is achieved by high NA lens... more In Full field Optical Coherence Tomography (FFOCT) lateral resolution is achieved by high NA lenses. However, it decreases depth of focus (DOF). We incorporate interfering phase mask allowing to extend the DOF of a FFOCT.
Elsevier eBooks, 2018
The properties of sculptured thin films (STFs) grown by glancing angle deposition (GLAD) make the... more The properties of sculptured thin films (STFs) grown by glancing angle deposition (GLAD) make them attractive for biosensing applications. Such biosensors, based on the enhancement of optical response signals of certain molecules, can be applied for detection of DNA, glucose, endocrine disruption compounds and bacteria. In this work, a short overview about the preparation of STFs by oblique angle deposition and GLAD is given. These techniques are capable to fabricate nanostructures with a wide variety of morphology by utilization of the atomic shadowing and the surface diffusion effects at highly oblique deposition angles. With the aim of the lateral separation of nanostructures, prepatterned template substrates can be introduced, which are characterized by uniformly separated seed elements that act as nucleation points for the nanostructure growth. The electromagnetic field enhancement in the vicinity of STF nanostructures is a highly attractive effect that is used by surface-enhanced Raman spectroscopy and surface-enhanced fluorescence spectroscopy to reduce the detection limits. The STF nanostructures are further functionalized to come as close as possible to this scientific intent. The details are discussed, and the subsequent chemical surface functionalization of the used sensors is shown. Specific and sensible detections of the endocrine disruptor biomarker protein vitellogenin, of glycated hemoglobin, and of E. coli bacteria are demonstrated.
Sensors, Mar 21, 2019
Plasmon waveguide resonance (PWR) sensors exhibit narrow resonances at the two orthogonal polariz... more Plasmon waveguide resonance (PWR) sensors exhibit narrow resonances at the two orthogonal polarizations, transverse electric (TE) and transverse magnetic (TM), which are narrower by almost an order of a magnitude than the standard surface plasmon resonance (SPR), and thus the figure of merit is enhanced. This fact is useful for measuring optical anisotropy of materials on the surface and determining the orientation of molecules with high resolution. Using the diverging beam approach and a liquid crystal retarder, we present experimental results by simultaneous detection of TE and TM polarized resonances as well as using fast higher contrast serial detection with a variable liquid crystal retarder. While simultaneous detection makes the system simpler, a serial one has the advantage of obtaining a larger contrast of the resonances and thus an improved signal-to-noise ratio. Although the sensitivity of the PWR resonances is smaller than the standard SPR, the angular width is much smaller, and thus the figure of merit is improved. When the measurement methodology has a high enough angular resolution, as is the one presented here, the PWR becomes advantageous over other SPR modes. The possibility of carrying out exact numerical simulations for anisotropic molecules using the 4 × 4 matrix approach brings another advantage of the PWR over SPR on the possibility of extracting the orientation of molecules adsorbed to the surface. High sensitivity of the TE and TM signals to the anisotropic molecules orientation is found here, and comparison to the experimental data allowed detection of the orientation of lipids on the sensor surface. The molecular orientations cannot be fully determined from the TM polarization alone as in standard SPR, which underlines the additional advantage of the PWR technique.
arXiv (Cornell University), Oct 23, 2018
Tunable narrowband spectral filters with high light throughput and wide dynamic range have remark... more Tunable narrowband spectral filters with high light throughput and wide dynamic range have remarkable applications such as in optical communications, optical spectroscopy and spectral imaging. However, a cost is usually associated with the filter narrowing either in the dynamic range, in the throughput or the manufacturability. Here we report on a resonating planar multilayered structure that exhibits transparency window in reflection with a controllable full width at half maximum (sub-Angstroms till tens of nm) and tunability over wide spectral range (>500nm in the visible and near infrared). The phenomenon is observed in TE and TM polarizations with much higher contrast in TE. Fano type resonance originating from coupling between waveguide modes and lossy surface electromagnetic waves supported by field distribution calculations explains the phenomenon. The wide tuning range with high contrast is mainly achieved using an absorptive layer with high imaginary to real part ratio of the dielectric constant that enables excitation of lossy surface waves known to exist over a wide spectral band in thin films. To avoid large losses, it is found that the lossy layer should be ultrathin (6nm Cr layer for example). The tuning is achieved by small angular scan of less than 2 degrees or by modulating the refractive index or thickness of the submicron thick waveguide layer from the visible till the near infrared range and in principle it can be designed to operate in any spectral range. Such a thin variable index or thickness layer can allow tuning at ultrahigh speed using conventional electrooptic, magnetooptic, piezoelectric or thermooptic materials at relatively low external fields.
We report on a fibre laser source which emits high peak power (>0.7 kW) and short (2.8 ns) Q-s... more We report on a fibre laser source which emits high peak power (>0.7 kW) and short (2.8 ns) Q-switched pulses at 1.06 µm suitable for distributed fibre sensor applications using an absorbed pump power of 13 mW and miniature acousto-optic modulator.
Publisher Summary This chapter reviews some of the fabrication techniques to be used for realizat... more Publisher Summary This chapter reviews some of the fabrication techniques to be used for realization of the integrated nanophotonic devices. Nanofabrication technologies are applied for the manufacture of nanoscale devices applicable to fields of research such as microelectronics or nanophotonics. Usually, the fabricated devices are made out of semiconductor materials, dielectrics, oxides, and metals. Most of the manufacturing processes of nanoscale devices consist of two basic stages—formation of an image on a surface of a material and processing and patterning the surface. In general, image formation on a surface of a chip may be obtained by means of deposition of a layer of a photosensitive material—photo-resist, or a material sensitive to an electron beam—electron-resist, or a material sensitive to an X-ray and then its exposition. There are several techniques and fabrication means capable of performing the exposition and realization of the devices. Frequently usable technological means include electron beam direct-write lithography, where scanning focused electron beam is used, atomic force microscopic (AFM) nanolithography where the image formation on the surface occurs by means of controlled movement of the sharp end of a tip, and optical mask-less lithography where spatial light modulation (SLM) devices may be used in order to form the photonic distribution on the surface of the device following controlled electric signals.
Elsevier eBooks, 2014
Publisher Summary This chapter focuses on various integrated modulation circuitry on silicon chip... more Publisher Summary This chapter focuses on various integrated modulation circuitry on silicon chips. It provides an analysis of several practical schemes. It focuses on several recently developed processing schemes in silicon that are allowing future incorporation of photonic devices with existing electronic processing chips. The intense involvement of industry in this field emphasizes its commercial value and the potential impact of this direction of research. Due to historic reasons, silicon has become the major platform for microelectronic processing boards. The fabrication facilities and factories are adjusted to operate with this material and its cost justifies its wide commercial usage. However, silicon has one major drawback. Although it exhibits some optics-related effects, such as the free-carrier plasma-dispersion effect and the thermo-optic effect, there is no significant evidence of the existence of other effects that are most often used in modulation devices. Nevertheless, it has been recently demonstrated that strained silicon exhibits a small electro-optic Pockels effect.
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Papers by Ibrahim Abdulhalim