Global Scientific Event on

Atomic, Molecular, and Optical Physics

Day - 1

...
Session : | Time:

SomeNoveltiesin LaserDrivenNonlinearPlasmonics


   Norbert Kroo
   Hungarian Academy of Sciences, Hungary

A set of unique results of nonlinear surface Plasmon (SPP) phenomena are presented. The SPP-s have been excited in a gold film by fem to second Ti: Salasers in the Kretschman geometry. Response signals to these excitations of a near field scanning tunneling microscope (STM) and spectra of SPP assisted electron emission by the time-of-flight (TOF) technique have been studied. Abroad spectrum of room temperature experimental observations is described here. Laser intensity dependent electron pairing and associated Meissner type magnetic anomalies have been found in a wide laser intensity range around 80 GW/cm2,The dynamical screening effect of electrons by the high plasmonic field is also described. Smooth and nano structured gold films have been studied. The plasmonic field enhancement effect in the structured sample is significantly higher. The SPP assisted electro emission and acceleration effect is also described. Narrow resonances” have been found in the time-of-flight spectra of electrons with anomalies in the laser intensity range of electron pairing. The temporal and quantum feature of these resonances is also discussed. Some further quantum properties of SPP-s are also presented, found both in the STM and TOF electron emission data. Some of the theoretical interpretations of our findings is also discussed. Some of these findings may serve as the basis for several new applications.

View Biography

  • 20
  • 40

Session : | Time:

Possible Implications for Discovery of Strong Radial Magnetic Field at the Galactic Center


   Qiuhe Peng
   Nanjing University, China, Nanjing

An abnormal strong radial magnetic field near the Galactic Center (GC) is detected[1]. The lower limit of the radial magnetic field at r=0.12 pc from the GC is . Its Possible scientific significances are following: 1) The black hole model at the GC is incorrect. The reason is very simple as follows. the radiations observed from the region neighbor of the GC are hardly emitted by the gas of accretion disk which is prevented from approaching to the GC by the abnormally strong radial magnetic field[2]. 2) This is an anticipated signals for existence of magnetic monopoles(MM)[3]. The lower limit of the detected radial magnetic field is quantitatively in agreement with the prediction of the paper “An AGN model with MM”[4]. 3) Magnetic monopoles may play a key role in some very important astrophysical problems usingthe Robakov-Callen effect that nucleons may decay catalyzed by MM Taking the RC effect as an energy source, we have proposed an unified model for various supernova explosion[5], including to solve the question of the energy source both in the Earth core and in the white dwarfs. 4) We may explain the physical reason of the Hot Big Bang of the Universe with the similar mechanism of supernova explosion by using the RC effect as an energy source. Reference 1) Eatough R.P., et al., 2013, “A strong magnetic field around the supermassive black hole at the centre of the Galaxy”, , Vol.591, 391-393. 2) Qiu-He Peng, Jing-Jing Liu and Chi-Kang Chou, 2016 “A possible influence on standard model of quasars and active galactic nuclei in strong magnetic field”, Astrophys Space Sci (2016) 361:388 3) Qiu-He Peng, Jing-Jing Liu and Zhong-Qi Ma, 2017, “Some new possible anticipated signals for existence of magnetic monopoles?” New Astronomy, 57 (2017)59-62 4) Peng Q. and Chou C., 2001, “High-Energy Radiation From a Model of Quasars, Active Galactic Nuclei, And the Galactic Center With Magnetic Monopoles”, ApJ., 551(2001) L23-L26 5) Qiu-He Peng , Jing-Jing Liu and Chih-Kang Chou, 2017, “A unified model of supernova driven by magnetic monopoles” Astrophys Space Sci , 2017, 362;222

View Biography

  • 20
  • 40

Session : | Time:

Benchmarking the Polyatomic Reaction Dynamics of X + Methane


   Kopin Liu
   Institute of Atomic and Molecular Sciences (IAMS), Academia Sinica, Taipei, Taiwan

With recent developments of sophisticated experimental techniques and advanced theoretical methods/computations, the fields of chemical reaction dynamics have reached to the point that theory‒experiment comparisons can be made at a quantitative level for a prototypical A + BC system. As the system becomes larger, more degrees of freedom are involved and thus many new chemistry and novel phenomena await to be discovered―a land of opportunities. Over the past 15 years my laboratory has delved to the reaction dynamics of methane + X (X: F, Cl, O(3P), and OH). This effort shifts the paradigm, making the title reaction a benchmark polyatomic system. In this talk, I shall highlight some of the key concepts introduced and unexpected phenomena uncovered. Those findings not only enrich our understanding of the studied reactions at the most fundamental level and inspire the theoretical developments, but also shape our thinking and lay the foundation for future explorations of different aspects of the multifaceted nature of polyatomic reactivity.

View Biography

  • 20
  • 40

Session : | Time:

The Use of Velocity Mapped Ion Imaging to Study Inelastic Scattering of Excited State Molecules.


   David W. Chandler
   Sandia National Laboratory, United States

Stereodynamics is the study of the impact of orientation and alignment of atoms and molecules on reactivity and the production of alignment and orientation of atoms and molecules from reactivity. One tool that has been instrumental in the observation of alignment and orientation has been the ion imaging technique with all of its variations. The use of polarized laser beams to resonantly produce ions that whose positions are measured allows one to measure, with little effort, the alignment or orientation of scattered products for a particular scattering velocity. Crossed molecular beam studies utilizing velocity mapped ion imaging have provided the first three and four vector-correlated studies of collisional dynamics. The crossed beams provide a definition of the incoming velocity vector and the ion imaging measures the alignment or orientation of the product for each product scattering velocity. When the reactants are produced in a manner that provides an alignment or orientation then four vectors are correlated and the dynamics of the collision is investigated with extreme precision. This provides a very stringent test for the theories of scattering and reactivity. Recent studies involving laser preparation of oriented species will be highlighted as well as previous studies that highlight the utility of this technique for the study of stereodynamics. In particular the scattering of laser prepared and oriented NO(A N=2) with Ne will be discussed.

View Biography

  • 20
  • 40

Session : | Time:

Generation of ultrafast Super-Continuum Laser Solar Simulator


   Walid Tawfik
   National Institute of Laser NILES,Cairo University, Cairo, Egypt.

This research reveals a new laser technology, the ultrafast supercontinuum laser, to produce a high power ultrafast controllable laser solar simulator. The system output irradiance of 31.8 x 1015 w/cm2 exceeds 300 Peta suns, assuming the typical sun irradiance is 0.1 w/ cm2. In this work, ultrafast high energy laser pulses have been observed. has been presented. These pulses were generated due to supercontinuum caused by self –phase modification (SPM) in neon gas filled in a one-meter hollow-fiber followed by two chirped-mirrors for dispersion compensation. The created pulses reached the transform limited of ~ 6 femtosecond pulse duration with high energy of sub-mJ at 1 KHz repetition rate. The characterization of ultrafast pulses in the regime of few-cycle pulses is considered using spectral phase interferometry for direct electric-field reconstruction (SPIDER). The SPIDER was used to observe precise measurements of pulse duration. The spectral bandwidth found to reach ultra-wide range from 600 – 950 nm. It has been found that the output pulse width is affected by the pulse duration of the injected femtosecond pulses into the optical fiber under different gas pressures. The observed results revealed that the nonlinear SPM increases the gas pressure. The obtained pulses can be used in ultrafast laser texturing for enhanced solar cell performance in future.

View Biography

  • 20
  • 40

Session : | Time:

Optical coherence tomography-from micron to nanometer resolution


   Sheng-Lung Huang1
   National Taiwan University, Taiwan

Optical coherence tomography (OCT) has been demonstrated as a powerful tool for characterizing biomedical tissues as well as microstructures in semiconductors, liquid crystal display panels, photonic integrated waveguides. Using broadband crystalline fiber based light sources from visible to near-infrared wavelength range, sub-micron resolution was achieved for non-invasive and label-free applications. The crystalline fibers were fabricated by the laser-heated pedestal growth method. Recent advancement on the codrawing laser-heated pedestal growth technique will be introduced in the talk. Since the axial resolution of OCT depends also on the center wavelength, nanometer resolution could be realized with the use of extreme ultraviolet (EUV) light source. A diode-laser seeded multi-stage fiber master oscillator power amplifier (MOPA) has been developed with millijoule pulse energy at a 6-nanosecond pulse width. To generate the 13.5-nm EUV, laser-produced plasma was excited using the MJ-MOPA system. In this talk, a novel EUV-based OCT with common-path configuration will be presented. As an example, the complex transfer function of a Si/Mo multilayer beam splitter is obtained. The measured thickness of the Si/Mo multilayer beam splitter agrees well with the one calculated from the fabrication parameters. The result strongly suggests the method s applicability as a new nondestructive tomographic tool for nanometer-scale actinic patterned EUV mask inspection.

View Biography

  • 20
  • 40

Session : | Time:

Measurement immune quantum key distribution using coherent light in a double Mach-Zehnder interometer


   Byoung S. Ham
   Gwangju Institute of Science and Technology, Korea

Due to the detection loophole, current quantum key distribution (QKD) cannot be unconditionally secured resulting in practical limitations. Moreover, the transmission distance through an optical fiber is limited not only by optical loss but also by polarization maintaining. Here, I propose the detection loophole-free QKD using coherence light in a double Mach-Zehnder interferometer (MZI), where the unconditional security is achieved by path superposition of the MZI. Owing to the coherence nature of light, the proposed measurement-immune QKD is compatible with current optical systems such as switches and amplifiers such that the transmission distance is unlimited. This opens a door to a completely new stage of QKD for practical applications of unconditionally secured cryptography in the near future.

View Biography

  • 20
  • 40

Session : | Time:

Mid-Ir Fluoride Fibers for Uv-Vis-Midir- fiber lasers


   Mohammed Saad
   Thorlabs Inc, United States

Fiber lasers have attracted a lot of attentions, because of their multiple advantages compared the other lasers technologies, such as semiconductor, gas and solid state lasers. Fiber lasers are compact and have high efficiency, excellent beam quality and exhibit good heat dissipation. They are currently used in many industrial (drilling, cutting and welding…) and high tech applications, such as defense and aerospace, medicine, spectroscopy and sensing. Since the first demonstration of the first fiber laser in 1964, by Snitzer et al., two research directions have been investigated; scaling the output power and investigating new laser lines. High power output fiber lasers have been already demonstrated using silica doped fibers. Fiber lasers with kilo watts output power have been achieved and used in industrial applications. As far as new wavelengths fiber lasers are concerned, other glass hosts have been intensively investigated, such as fluoride, phosphate, chalcogenide and tellurite glasses. No one of these glasses can fulfil the need of all applications. Scientist and engineers have to consider the right glass host for the right application. However, the right candidate has to combine the ability to be drawn into high quality single mode optical fiber, have a high solubility of rare-earth ions and the ability to be cleaved and spliced. A wide transmission window is also advantageous along with the ability to write Bragg Gratings in the fiber to tailor the emission characteristics. The presentation will report the latest development in fluoride glass fiber technology and their applications

View Biography

  • 20
  • 40

Session : | Time:

Laser Induced Damages in Multilayer Oxide Thin Films


   Ajay Shankar
   Guru Jambheshwar University Of Science and Technology, India

The high power laser beam generation and manipulation depends on laser induced damages threshold (LIDT) of optical components used in the system. LIDT for such components having multilayers thin film coatings used to improve performance of coatings has been subject of intensive investigations. We studied conventional electron beam deposited multilayer coatings made with lower index oxide essentially SiO2 and examining performance variations with its combination with a set of high index materials layer TiO2 ,Ta2O5 ,and HfO2 on Quartz/BK-7 substrate all quarter wave optical thickness(QWOT) and with few outer non-QWOT layers. One of our primary aims is to study effect of multilayer boundary and related effect for their combination as all quarter wave high and low index material films layers when number of layers increases as well allowing upper two non-quarter wave thickness layers. One of critical parameter observed to effect the LIDT were found to be location of electric field peaks proximity with the boundaries of low and high index layers in any multilayer laser optics particularly at few front boundaries where field strengths are invariably high. Reflection spectra of these samples shows a relatively small decrease in reflection in non-quarter wave layer design and GIXRD showed that deposited films are amorphous, sufficient high refractive index and very low extinction coefficient or low absorption as factors favorable for high laser induced damage threshold. LIDT studies were needed to be performed starting with s single layer of oxides to all quarter wave and combination of QWOT and non-QWOT to adjust field positions increasing LIDT of coated multilayer stack.

View Biography

  • 20
  • 40

Session : | Time:

Thin film deposition by Laser-induced forward transferring technique for industrial application


   Mohammad Hossein Azhdast
   Technical University of Berlin, Germany

The goal of this presentation is to introduce and perform a modern study of Laser deposition for thin films and structuring in industrial applications.Laser-induced forward transfer (LIFT) is a laser-based additive of direct-write techniques in which laser pulses are implemented to the material from a donor film and deposit it in a receptor substrate.This method can print droplets of solutions and also micro/nano particles with a high resolution.LIFT techniques provide some opportunities for models, forms, and devices which cannot handle traditional photolithography tools and they are perfectly suitable for digital micro-fabrication applications.Practical application of laser-induced forward transfer is still in early stages; however vast technologies have been demonstrated for different utilization.Surface engineering has a crucial role as the improvement or modification of a surface by using thin coatings. This simple, fast, one-step technique has great application potential in research on micro- and nano-device fabrication. The range of applications are different, extending from various tasks to some applied reasons such as developing electrical features, bio-compatibility, metal grids in solar cell applications (CIGS), improvements of electrical wire interconnections such as Molded Interconnect Device (MID) in the automotive industry and wire bonding.

View Biography

  • 20
  • 40

Session : | Time:

Effect of Particle Size on Optical Properties of Vanadium Oxide Nanoparticles


   Devendra Mohan
   Guru Jambheshwar University of Science and Technology, India

The linear and nonlinear optical properties of electro-deposited Vanadium Oxide mesoporous structure on ITO sheet have been studied. The characterization is done using UV-VIS-NIR spectrometer, SEM, FTIR and XRD. A good transmission has been observed in IR range and there is increase in band gap due to decrease in grain size resulting blue shift of light emission band. Nonlinear behavior measurement has been studied using a single beam Z-scan method with He- Ne Laser of λ ~ 632 nm. The nonlinear refractive index and the nonlinear absorption coefficient of samples have been determined for nano-particle sizes ranging from 10 to 40 nm. However, the nonlinear absorption coefficient rapidly decreases with increase in particle size. The third order nonlinear susceptibility of all the samples is also calculated and discussed. It is observed that the response of the V2O5 nanostructures to the incident laser beam varies depending on the particle size. The increase in optical susceptibility due to decrease in particle size make the Vanadium Oxide as a potential material for optoelectronic devices.

View Biography

  • 20
  • 40

Session : | Time:

Investigations of plasma into the magnetically uniform Confined plasma


   Samir Suliman Yassin
   Islamic University of Gaza

One of the most important purposes of magnetic confinement is to keep the hot plasma away from the wall of the vacuum vessel. The temperature required to sustain fusion reaction is the order of 10 Kev. The interaction between charged particles and magnetic field , are used to keep hot plasma from coming contact with the wall the vacuum vessel . Some of the ions escape from the hot plasma reaches a layer , and interact with the impurity atoms of high atomic mass into the vacuum area . The machine is been modified to provide high density of plasma. The plasma is produced externally from source , and confined in a cylindrical geometry at low magnetic 1kG. The calculation has been made and suggested that the ion beam in the solenoid will have a maximum radius of twice the Larmor radius , while the density is a complex function of the ratio B (Z.)/Bm. The low density obtained , suggesting that losses due to mirroring may be occurring that is the plasma source should be closer to solenoid to provide good plasma injection.

View Biography

  • 20
  • 40

Session : | Time:

Fabrication and Optical Characterization of Polyvinylidene Fluoride/Neodymium Oxide Nanocomposite Films


   M. D. Aggarwal
   Alabama A&M University, USA

Ferroelectric materials are called smart materials as they can be configured to store, release, or interconvert electrical and mechanical energy in a well-controlled manner via their respective characteristics. They have exceptionally large piezoelectric compliances, pyroelectric coefficients, dielectric susceptibilities, and electro-optic properties. Thus, are attractive for variety of applications such as high energy density capacitors, actuators, sensors, ultrasonic imaging devices, pyroelectric thermal imaging devices, gate insulators in transistors, electro-optic light valves, thin-film memory elements, multiferroic transducers, energy harvesters, etc. Ferroelectric polyvinylidene fluoride (PVDF) is utilized in a wide range of devices due to their excellent mechanical properties, optical, high thermal and chemical stability, piezoelectricity, pyroelectricity, and ferroelectric responses. In the present investigation, the pristine and neodymium oxide (Nd2O3) nanoparticles embedded poly vinylidene fluoride (PVDF) thick films were fabricated via solution casting/intercalation technique. The Nd2O3 nanoparticles were synthesized via hydrothermal technique. The Fourier Transform Infrared Spectroscopy (FTIR) has been recorded in the range 500 to 4000 cm-1 and functional groups were identified in the nanocomposite films. Infrared vibrational spectroscopy (FTIR/Raman) revealed intrinsically presence of ferroelectric β-phase in the annealed nanocomposite films. All-important optical constants have been determined for the first time via UV-VIS transmission spectroscopy for the nanocomposite films in the ferroelectric phase. The ultraviolet-visible spectra showed that the fabricated firms have wide optical transparency in the entire visible region. The partial support for this work through the National Science Foundation (NSF) grant RISE-HRD 1546965 is acknowledged

View Biography

  • 20
  • 40

Session : | Time:

Self-assembly of PVPylated Surfactants into Stable Niosomes as Potential Pharmaceutical Carriers


   Muhanna K. Al-Muhanna
   King Abdulaziz City for Science and Technology (KACST), Saudi Arabia

A range of novel, nonionic polymeric surfactants containing short, hydrophilic polymeric chains polyvinylpyrrolidone PVP have been investigated for their ability to form vesicles for drug delivery. The designated formula of these surfactants was 2CmglyVPn where m is the length of the hydrophobic chains, n is the length of the hydrophilic head group, and gly that surfactants contained a glycerol backbone. The length of the hydrophilic head groups ranged from 25 to 50 while the length of the two hydrophobic chains present ranged from C12 to C18. The ability of the polymeric surfactants to form vesicles, both in the absence and presence of cholesterol, using the thin film method in combination with probe sonication investigated using a range of analytical techniques, specifically light and neutron scattering, electron microscopy and dye entrapment studies. The change in aggregate size with duration of probe sonication assessed using light scattering, as was vesicle stability over time. Small angle neutron scattering (SANS) studies confirmed the presence or otherwise of vesicles and, in the case of vesicle formation, allowed quantification of the thickness (and where appropriate the repeat distance) of the vesicle bilayers. The effect on vesicle formation of 0.9M sodium chloride was also established by SANS. The dye entrapment and electron microscopy studies confirmed the results of the light scattering and SANS studies. The stability of the aggregates to incubation for 24 hours with human blood plasma at 298 and 310 K was assessed by monitoring the release of any entrapped CF. In order to form stable vesicles, the PVP-based surfactants needed to be mixed with at least 50 mol % cholesterol. In contrast, the PAM-containing surfactants did not appear to readily form vesicles even when mixed with cholesterol at 66 mol %.

View Biography

  • 20
  • 40

Session : | Time:

Electron acceleration by radially-polarized laser pulses in plasma micro-channels and from solid wires


   Meng Wen
   Max-Planck-Institut für Kernphysik, Germany

Encouraged by recent advances in radially-polarized laser technology, three-dimensional Particle-In-Cell simulations have been performed of electron acceleration by an ultra-short pulse in a parabolic plasma micro-channel and along a solid-wire. In the miciro-channel, milli-joule laser pulses, generated at kHz repetition rates, are shown to produce electron bunches of MeV energy, pC charge, low emittance and low divergence. The pivotal role played by the channel length in controlling the process is demonstrated, and the roles of direct and wakefield acceleration are distinguished. With a solid target, electrons may be generated and subsequently accelerated to energies of the order-of-magnitude of the ponderomotive limit, with the underlying process dominated by direct laser acceleration. Breaking this limit, realized here by a radially-polarized laser pulse incident upon a wire target, can be associated with several novel effects. Simulations show a relativistic intense laser pulse can extract electrons from the wire and inject them into the accelerating field. Anti-dephasing, resulting from collective plasma effects, are shown to enhance the accelerated electron energy by two orders of magnitude compared to the ponderomotive limit. It is demonstrated that ultra-short radially polarized pulses produce super-ponderomotive electrons more efficiently than pulses of the linear and circular polarization varieties.

View Biography

  • 20
  • 40

Session : | Time:

Photodetachmennt of Atomic Negative Ion in the Presence of Nano-Surface


   Muhammad Haneef
   Hazara University Mansehra, Pakistan

Photo detachment of Atomic negative negative ion in the vicinity of nano-surface has been investigated. Atomic negative ion, if exposed to light behaves detaches electron. The detached electron tags by a wave packet which is greatly manipulated by the presence of nano-surfaces. The wave packet is exploited for the derivation of photo detachment cross section. The reflection and tunneling of waves from nano surface is discussed. Size of the surface along the absorption parameter strongly influence the photodetachment spectra. However, a fine control on these parameters can be used to investigate the information of negative ions, curvature, roughness in the surface at nano scale.

View Biography

  • 20
  • 40

Session : | Time:

A Theoretical Study of Copper Sulfide Nanoalloy Clusters: Density Functional Approach


   Tanmoy Chakraborty
   Department of Chemistry, Manipal University Jaipur, India

Importance of Nano clusters of Copper sulfides (CuS) is well known due to its interesting properties. Our group have studied nanoalloy clusters of (CuS)n; (n = 1–8) in terms of Conceptual Density Functional Theory (CDFT) based descriptors, aiming to explore its electronic and other properties. Global DFT based descriptors have been computed for ground state configurations and low-lying isomers of (CuS)n clusters. Our computed HOMO-LUMO energy difference, lying in the range of 1.25–3.53 eV, indicate possibility of utilization of (CuS)n clusters as renewable energy sources specially in photocatalysis and solar cell applications. A statistical regression analysis has been made between electronic and photo-catalytic properties of copper-sulfide clusters with their computational counterparts. The close agreement between experimental and computed data strengthens our analytical approach.

View Biography

  • 20
  • 40

Session : | Time:

Double and Triple Autoionization of Atomic Ions Atoms


   Shahin Ahmed Abdel Naby
   Department of Physics, American University of Sharjah, United Arab Emirates

A time-dependent close-coupling (TDCC) method was successfully used to study ionizations arising from interactions of electrons, photons, and ions with small atoms and molecules. Currently, this method is developed to handle a four-electron system initially in an excited state such as C2+ (2s22p2). The C2+ (2s22p2) excited state can be obtained by relaxation of Schrodinger’s equation in imaginary time. Double, triple, and total autoionization rates for C2+ are obtained by propagation in real time using projections onto products of bound and continuum single particle states. This work was motivated by recent experimental measurements of single, double, and triple autoionization of C+ ion by single photons. Future developments for the TDCC approach are underway to handle a five-electron system with interior subshells such as C+ (1s2s22p2). The work was supported in part by grant from American University of Sharjah. Computational work was carried out at the national Energy Research Scientific Computing Center (NERSC) in Berkeley, California, USA.

View Biography

  • 20
  • 40

Day - 2

...
Session : | Time:

Novel Ion Source under Double-Pulse Laser Ablation Technique


  Ahmed Asaad Ibrahim Khalil
  NILES, Cairo University, Giza, Egypt

Novel metal ion source is developed by using double-pulse lasers ablation (DPLA) technique and create high current under applying an electric potential in an ambient gas environment. Two Q-switched Nd:YAG lasers operating at infra-red (IR) and ultra violet (UV) wavelengths are combined in an unconventional orthogonal double-pulse (DP) configuration with 43o angle to focus on a metal target along with a spectrometer for spectral analysis of metal plasma. The properties of metal plasma generated under DP lasers excitation were studied. The velocity distribution of the emitted plasma cloud is carefully measured using a dedicated ion probe (FCIP). Multicharged metal ions are produced in a high vacuum. Electrostatic retarding field ion energy analyzers and time-of-flight are utilized to record the laser-created multicharged ions. The production of ions with a higher charge state is also recorded with the increase in the laser pulse energy. The experimental parameters is optimized to attain the best signal-to-noise ratio of the emission spectra. The results show that the increase in the metal ion velocity under the DP lasers causes the output current signal to increase by about six-folds. Spatially-resolved optical spectra and time-integrated are utilized to attain the plasma density and excitation temperature. The transition probabilities and energy states were computed using Hibbert’s configuration interaction, computer package (CIV3). We also proposed a theoretical population model in order to investigate the effectiveness of the various processes that might affect the population of the upper levels in metal plasma by using the rate coefficients. Good compatibility between the experimental and the theoretical model data had been observed. The plasma parameters are calculated using the Stark-broadened line profile of spectral line and a Boltzmann plot method of the upper energy levels, respectively. In addition the dependence of the plasma parameters on the delay (times between the excitation laser pulse and the opening of camera shutter) was investigated as well. The signal intensity dependence of the ion angular distribution is also analyzed. This study could provide significant reference data for the optimization and design of DPLA configuration for generating more metal ion source to be used in laser induced plasma deposition thin films, implantations and facing components diagnostics.

View Biography

  • 20
  • 40

Session : | Time:

Nanometric study of transport phenomena in InN / InP semiconductor electronic devices.


  Hadjadj Brahim
  SFTE, Algeria

The III-V compound semiconductors based on nitrogen (InN, GaN), are today very promising in the field of microelectronics and optoelectronics. Element III nitrides are particularly attractive substrates for short wavelength optoelectronic applications. The major advantage of this family of materials lies in their very wide band gap and their electronic properties of saturation speed and high breakdown field. In the field of microelectronics, nitrides are the best candidates for all high temperature, high power or high frequency applications. III / V semiconductor substrates such as InP are valuable materials for the growth of InN potentially. However, the characteristics of the resulting heterojunctions are closely related to the surface and the interface state. This work deals with the nanometric study of the transport phenomena in the electronic devices of III-V and III-N semiconductors, in particular InP and InN. Key words: III-V semiconductors, heterojunctions, nitrides.

View Biography

  • 20
  • 40

Session : | Time:

Two-Dimensional Excitonics for Giant Optical Nonlinearity in the Near-IR


  Wei Ji
  National University of Singapore

As emerged recently, Excitonics is related to the understanding, control and harnessing of optically-excited, electron-hole pairs (or Excitons) in nanoscale environments. Here, for the first time, we present our two-dimensional excitonic models [1 - 4] to quantitatively predict the giant optical nonlinearity in terms of Two-Photon Absorption (2PA) and Three-Photon Absorption (3PA), for monolayer transition-metal di-chalcogenides or layered organic-inorganic hybrid perovskites. Based on quantum mechanical perturbation theories, our theoretical models predict that the 2PA or 3PA coefficients should be as large as ~ 30 cm/MW, or ~ 3 cm3/GW2, respectively, at room temperature. By decreasing the operating temperature to 77 K, an enhancement of three-orders-of-magnitude should be anticipated by the models. To verify our models and to demonstrate such giant multi-photon absorption for photoconduction or light frequency up-conversion, we fabricate an exfoliated monolayer MoS2 sub-band photo-detector, or layered organic-inorganic hybrid perovskites for light frequency up-converters. From photocurrent or photoluminescence measurements with femtosecond-laser-pulse excitation in the near-IR spectrum, we experimentally determine the 2PA and 3PA spectra of monolayer MoS2, or, the 3PA spectra of layered organic-inorganic hybrid perovskites, respectively. We find that our models are in agreement with the measurements, within one order of magnitude.

View Biography

  • 20
  • 40

Session : | Time:

Nature of Physical Reality: A Critical Assessment of Material Realism


  Behnam M. Zadegan
  Retired university professor, presently a private contractor

After Renaissance, European natural scientists and philosophers agreed on a scientific view of the nature of physical reality based entirely on Newtonian physics. The agreed view on the nature of reality has been known as material realism. This paper presents a critical assessment of the set of scientific facts which proponents of material realism had agreed up on in support of their post-Renaissance view on the nature of reality. First, for the sake of clarity, this set of scientific facts, is specifically described. Next, these scientific facts are critically assessed in light of specific scientific discoveries which took place after the late 1870’s. This paper argues that scientific discoveries after the late 1870’s, do not support the principle assumptions of the material realism view on the nature of reality. Specifically, the relevance of a number of well-known scientific discoveries, including Maxwell’s electromagnetic theory, quantification of photon energy and the photon-electricity phenomenon, Planck’s blackbody radiation, Einstein’s general relativity theory, Hubble’s observations on the universe’s expansion, Einstein’s field equations and quantum theory arepresented in more details.

View Biography

  • 20
  • 40

Session : | Time:

Amorphous Plasmonic Metasurface-based Graphene Near-infrared Superabsorbers


  ChunYu Lu
  Mechanical and Materials Engineering, Khalifa University, Abu Dhabi, United Arab Emirates.

We experimentally demonstrate a hybrid amorphous metasurface-based graphene perfect absorber by alternatively combining the magnetron sputtering deposition with graphene transfer coating. The thickness constraint of physical vapor deposited amorphous metallic surface is unlocked, the as-fabricated metasurface-based graphene absorber achieves near-perfect absorption in the near-infrared regions with a ultra-board spectral bandwidth (FWHM) of 5.0μm. Our experimental characterization and theoretical analysis further points out that the strong light-matter interactions are caused by the localized surface plasmon resonace of the particle-like surface morphology. In addition to the enhancing light absorption, such an amorphous metasurface can be used for surface-enhanced Ramna scattering applications. Meanwhile, the proposed metasurface-based graphene coating just relies on CMOS-compatible simple, low cost and large-area processing, which can be flexibly constructed in mass-production scale.

View Biography

  • 20
  • 40

Session : | Time:

Adaptive neural network algorithm for power control in nuclear power plants


  Husam F. ALmasri
  Department of advanced nuclear Technology, Jordan Atomic Energy Commission., Jordan.

The objective of this paper is to design, test, and evaluate a prototype of an adaptive neural network algorithm for the power controlling system of a nuclear power plant. The task of power control in nuclear reactors is one of the most important tasks in this field. Therefore, researches are constantly carried out to improve the power reactor control process. Nowadays, in the department of Automation in National Research Nuclear University MEPhI many studies utilizing various methodologies of artificial intelligence (expert systems, neural networks, fuzzy systems and genetic algorithms) to enhance the performance, safety, efficiency and reliability of nuclear power plants. In particular, a study of an adaptive artificial intelligent power regulator in the control systems of nuclear power reactors is carried out to improve the performance and to minimize the output error of the Automatic Power Controller APC on the grounds of on multifunctional computer analyser (simulator) of the reactor VVER. In this paper, a block diagram of an adaptive reactor power controller was built on the basis of an intelligent control algorithm. When implementing the intelligent neural network principles, it is possible to improve the quality and the dynamic of any control system in accordance with the principles of adaptive control. As it is known, adaptive control system allows adjusting the controller s parameters according to the changes in the characteristics of the control object or external disturbances. In this project, it is shown that the promising options for an automatic power controller in nuclear power plants is a control system based on an intelligent neural network algorithms

View Biography

  • 20
  • 40

Session : | Time:

Study of the Structural, Microstructural and Thermal Characterization of 5% Fe-doped ZnO Powder Nanostructures Prepared by Mechanical Alloying


  Salah OUDJERTLI
  Badji Mokhtar - Annaba University | UBMA, Algeria

ZnO powder nanoparticles mechanically alloyed were doped with iron to investigate their structural and microstructural properties using X-ray diffraction (XRD) and differential scanning calorimetry ( DSC ) for examined 5% Fe doped ZnO. The ZnO starting pure powder exhibited a hexagonal crystal structure with space group p63mc of ZnO, however with the introduction of 5% Fe in the ZnO milled powder, the hexagonal ZnO phase remained unchanged, whereas the microstructural parameters were subject to significant variations due to the introduction of Fe atoms into the ZnO hexagonal matrix to replace oxygen ones. The size of crystallites and microstrains are found milling time dependent.

View Biography

  • 20
  • 40

Session : | Time:

Electromagnetic excitations in a nonideal array of microcavities with ultracold quantum dots


  Vladimir V. Rumyantsev
  A.A. Galkin Donetsk Institute for Physics and Engineering, Ukraine

The report is devoted to elucidation of the effect of point-like defects on electromagnetic excitations (polariton) dispersion in a 1D and 2D microcavity (microresonator) array with embedded one-level quantum dots. It is shown that the presence of vacancies in the microcavity and atomic (quantum dots) subsystems results in a substantial renormalization of polariton spectrum and thus in a considerable alteration of optical properties of the structure. Introduction of defects leads to an increase in the effective masses of polaritons and hence to a decrease of their group velocity. Our model is primarily based on the virtual crystal approximation, which is often employed to examine quasiparticle excitations in sufficiently simple disordered superstructures. More complex systems usually require the use of more sophisticated methods such as the (one- or multinode) coherent potential approximation, the averaged T-matrix method and their various modifications. The obtained numerical results contribute to our understanding of composite polaritonic structures and the prospects of their utilization for construction of solid-state devices with controllable propagation of electromagnetic waves.

View Biography

  • 20
  • 40

Session : | Time:

Sustainable Development of Bioenergy from Agriculture Residues and Environment


  Abdeen Omer
  Energy Research Institute, Nottingham, UK

This communication discusses a comprehensive review of biomass energy sources, environment and sustainable development. This includes all the biomass energy technologies, energy efficiency systems, energy conservation scenarios, energy savings and other mitigation measures necessary to reduce emissions globally. The current literature is reviewed regarding the ecological, social, cultural and economic impacts of biomass technology. This study gives an overview of present and future use of biomass as an industrial feedstock for production of fuels, chemicals and other materials. However, to be truly competitive in an open market situation, higher value products are required. Results suggest that biomass technology must be encouraged, promoted, invested, implemented, and demonstrated, but especially in remote rural areas.

View Biography

  • 20
  • 40

Session : | Time:

Capabilities at Jordan Research and Training Reactor


  Salih Majeed Alkhafaji
  Jordan research and Training reactor, Jordan, HKJ

Jordan Research and Training Reactor (JRTR) is a 5 MW open pool in-tank reactor, Fueled with LEU of 19.75% Uranium Silicide, light water cooled and moderated. Heavy water and beryllium blocks are the reflector material. JRTR is a multipurpose reactor with various capabilities such as Radioisotope Production (RI), Neutron Activation Analysis (NAA), Neutron Transmutation Doping (NTD) and Neutron Beam Applications. Three irradiation holes in the reactor reflector region are dedicated for NAA and are equipped with a pneumatic transfer system that facilitates sample irradiation in JRTR core. One NAA hole located near the core provides high and relatively hard neutron flux. Epithermal neutron NAA is possible using this hole by short irradiation of a sample in a Cd container. Two other holes rather far from the core provide lower and softer neutron flux. In addition there are three currently utilized irradiation channels for the production of radioisotopes namely, I-131, Mo-99/Tc-99m and Ir-192. The JRTR has started marketing the I-131 to the Jordanian hospitals since 19, Dec, 2018.

View Biography

  • 20
  • 40

Session : | Time:

Giant ultrafast nonlinear refraction in transparent conducting oxides


  David J Hagan
  College of Optics and Photonics, University of Central Florida

We present beam deflection measurements to study the nondegenerate nonlinear refraction of highly doped semiconductors at epsilon-near-zero (ENZ) for several different pump and probe polarizations. Beam deflection is sensitive to induced optical path length as small as 1/20,000 of a wavelength, which enables us to resolve NLR in the presence of large nonlinear absorption backgrounds. The optically induced index changes in these materials can be both very large (on the order of unity) and fast (on the order of 100 fs). Our results show that carrier redistribution effects dominate the nonlinear refraction, and by independently tuning the pump and probe wavelengths, we find that the strong wavelength dependence of nonlinearities around the ENZ point is quite different for pump and probe waves. These nonlinear optical properties, where the ultrafast index change can be larger than the linear index, offer new paradigms for dynamically switchable diffractive elements that respond to structured light, allowing manipulation of optical beams in transmission and reflection not only along the two spatial dimensions but also in time. This is a revolutionary change in the field of nonlinear optics allowing a myriad of potential applications, ranging from rapid all-optical beam steering and switching, to spectral scanning, spatial mode conversion, as well as pulse shaping and suppression, all on sub-picosecond time scales.

View Biography

  • 20
  • 40

Session : | Time:

Synthesis and Characterization of MoO3 Nanomaterials for Super capacitor application


  Atul K. Gupta
  Department of Physics, Allahabad Degree College, University of Allahabad, India.

Nanomaterials are being adapted into a number of applications across multiple domains such as in cosmetics, optical components, biology, physics, chemistry, polymer science, pharmaceutical drug manufacture, toxicology, and mechanical engineering. Here h-MoO3 and α-MoO3 nanorods were synthesized by salvothermal method. The morphology and structure of samples were characterized by SEM (scanning electron microscope) and XRD at different temperature. The electrochemical properties of the nanorods of MoO3 were characterized by cyclic voltametry. XRD analysis show that particle size increases as its temperature increases and the corresponding strain decreases also. SEM morphology shows its Nanorods structure, and the band gap is characterized by UV-visible spectroscopy. Its supercapacitive properties were also analyzed at different temperature.

View Biography

  • 20
  • 40

Session : | Time:

Strain-induced Flexoelectric Related Effects in Bi2Te3 Films


  Ning Dai
  State Key Laboratory of Infrared Physics, Shanghai Institute of Technical Physics, Chinese Academy of Sciences, China

As a typical 3D topological insulator, Bismuth Telluride (Bi2Te3) and its alloys have recently attracted significant interests due to their unique layered structures. In fact, they are also well-known thermoelectric materials with high thermoelectric coefficient near room temperature (RT) for applications in waste-heat recovery, refrigeration or portable power generation, since they possess notable properties such as a prominent Seebeck effect, low thermal conductivity and high value of the carrier concentration in RT. In addition, Bi2Te3 is a narrow bandgap semiconductor (0.15 eV at RT) and has been used to fabricate infrared detectors. Herein, notable flexoelectric effect has been observed in strained Bi2Te3 films owing to the stress gradient. Utilizing this effect, the bulk photovoltaic effect (BPVE) has been extended to the infrared wavelengths in these films, which was only found in wide band-gap ferroelectric materials before. Furthermore, an anomalous thermoelectricity in strained Bi2Te3 films, i.e., the value of Seebeck coefficient S that changes after reversing the direction of temperature gradient, has also been demonstrated. This effect provides a new avenue to adjust the S of Bi2Te3-based thermoelectric materials through flexoelectric polarization.

View Biography

  • 20
  • 40

Session : | Time:

Implantation-induced Lattice Strains and Defects in InAs0.93Sb0.07 films


  Huiyong Deng
  State Key Laboratory of Infrared Physics, Shanghai Institute of Technical Physics, Chinese Academy of Sciences, China

The ternary alloy InAs1-xSbx is a promising material for infrared optoelectronic device applications such as infrared laser, LED and photodetector, due to its better stability than popularly-used HgCdTe. Owing to light atom mass and low damage introducing rate, Be ion is a good choice for p-type doping in InAs1-xSbx through ion implantation. Unfortunately, ion implantation is a non-equilibrium technique, which often causes lattice damages. Herein, InAs0.93Sb0.07 epitaxial layer grown by liquid epitaxy growth (LPE) was implanted with Be ions. The characteristics of damage buildup and its removal by rapid thermal annealing at temperature 500 C were investigated by high resolution X-ray diffraction and TEM. The implantation-induced nonlinear maximum perpendicular strain m as a function of the Be fluence was obtained. The nonlinear strain was analyzed in terms of point defects. In addition, we found that the caused damages can be recovered by rapid thermal annealing at 500 C for samples with the fluence below 1.01015 cm2. Nano-sized residual damages after annealing at 500 C, however, were still observed when the fluence reaches 4.01015 cm2. Those residual damages might originate from poor recrystallization of the small disorder region.

View Biography

  • 20
  • 40

Day - 3

...

Poster

...

Electromagnetic excitations in a nonideal array of microcavities with ultracold quantum dots


  Vladimir V. Rumyantsev
  A.A. Galkin Donetsk Institute for Physics and Engineering, Donetsk, Ukraine

The report is devoted to elucidation of the effect of point-like defects on electromagnetic excitations (polariton) dispersion in a 1D and 2D microcavity (microresonator) array with embedded one-level quantum dots. It is shown that the presence of vacancies in the microcavity and atomic (quantum dots) subsystems results in a substantial renormalization of polariton spectrum and thus in a considerable alteration of optical properties of the structure. Introduction of defects leads to an increase in the effective masses of polaritons and hence to a decrease of their group velocity. Our model is primarily based on the virtual crystal approximation, which is often employed to examine quasiparticle excitations in sufficiently simple disordered superstructures. More complex systems usually require the use of more sophisticated methods such as the (one- or multinode) coherent potential approximation, the averaged T-matrix method and their various modifications. The obtained numerical results contribute to our understanding of composite polaritonic structures and the prospects of their utilization for construction of solid-state devices with controllable propagation of electromagnetic waves.

View Biography

  • 20
  • 40

Modelling a plasma accelerator driven FEL


  Badriah Alotaibi
  Strathclyde, Saudi Arabia

This work provides an introduction to the physics of coherent radiation sources using free electron beams. It is a Free Electron Lasers (FEL), and makes a comparison with conventional laser sources. Along this work, we will define several fundamental points , such as the principles of plasma acceleration. In addition, we will explain the FEL principles, compare them to the conventional systems, in order to demonstrate why FEL can be considered as important sources of increasing number of applications owing to their wide range of tunability and high brightness.

View Biography

  • 20
  • 40

Video Presentation

...