024194   RODRIGUEZ-MORALES L A, ARMAS-RIVERA I, AVAZPOUR M, BELTRAN -PEREZ G, SANTIAGO-HERNANDEZ H, IBARRA-ESCAMILLA B, DURAN-SANCHEZ M, POTTIEZ O, KUZIN E A (INAOE, Mexico, Email: beto.rodriguez@inaoep.mx) : Experimental investigation of polarization imbalanced nonlinear loop mirror with double-sense twisted fiber as a filter to clean up solitons. J Optics 2018, 20(1), 15502.

In the present work, we report the implementation of a novel polarization-imbalanced NOLM for soliton cleaning. The NOLM consists of a nearly symmetrical coupler with a 51/49 coupling ratio, and the fiber loop which, in contrast to previously reported results, consists of two 100 m pieces of fibers twisted in opposite directions. The use of the symmetrical coupler and two fiber spans twisted in opposite direction allowed a transmission of low-power radiation of 0.5 × 10⁻³ in the wavelength range of 1520–1560 nm. The maximum transmission at high power was 45 % providing 30 dB contrast between high and low power transmission. We show more than 20 dB suppression of Kelley’s side bands of 0.6 ps pulses from the output of the fiber mode-locked laser. The experimental results are supported by the numerical simulation and show that cleanup of solitons is possible using a NOLM as intensity filter without dependence of wavelength.

1 illus, 29 ref

024193   RACZ P, AGADI V, DOMBI P (Wigner Research Centre for Physics, Budapest-1121, Email: racz.peter@wigner.mta.hu) : On the role of rescattering and image charge in ultrafast nanooptical field probing with electrons. J Optics 2018, 20(1), 15501.

Photoemission induced by nanoplasmonic near-fields enables several intriguing applications such as measurement of nanooptical field enhancement and ultrafast electron microscopy. Here, we investigate the influence of electron rescattering and image charge on nanoplasmonic photoemission and electron acceleration processes induced by femosecond laser pulses. Our simulations confirm that electron rescattering determines essentially the final maximum kinetic energies of electrons, being essential for nanoplasmonic field probing. On the other hand, no significant effect was shown from the image charge in a broad parameter range. These results confirm the robustness of a recently demonstrated measurement method for nanoplasmonic field enhancement (Rácz et al 2017 Nano Lett. 17 1181).

5 illus, 28 ref

024192   GU H, CHEN X, ZHANG C, JIANG H, LIU S (Huazhong Univ of Science and Technology, Wuhan 430074, People’s Republic of China, Email: hjiang@hust.edu.cn) : Study of the retardance of a birefringent waveplate at tilt incidence by Mueller matrix ellipsometer. J Optics 2018, 20(1), 15401.

Birefringent waveplates are indispensable optical elements for polarization state modification in various optical systems. The retardance of a birefringent waveplate will change significantly when the incident angle of the light varies. Therefore, it is of great importance to study such field-of-view errors on the polarization properties, especially the retardance of a birefringent waveplate, for the performance improvement of the system. In this paper, we propose a generalized retardance formula at arbitrary incidence and azimuth for a general plane-parallel composite waveplate consisting of multiple aligned single waveplates. An efficient method and corresponding experimental set-up have been developed to characterize the retardance versus the field-of-view angle based on a constructed spectroscopic Mueller matrix ellipsometer. Both simulations and experiments on an MgF₂ biplate over an incident angle of 0°–8° and an azimuthal angle of 0°–360° are presented as an example, and the dominant experimental errors are discussed and corrected. The experimental results strongly agree with the simulations with a maximum difference of 0.15° over the entire field of view, which indicates the validity and great potential of the presented method for birefringent waveplate characterization at tilt incidence.

10 illus, 46 ref

024191   CUN P, WANG M, HUANG C, HUANG P, HE X, WEI Z, ZHANG X (Beijing Univ of Technology, Beijing 100124, People's Republic of China, Email: zhangxinping@bjut.edu.cn) : Conductive connection induced speed-up of localized-surface-plasmon dynamics. J Optics 2018, 20(1), 14011.

Conductive connection of localized surface plasmons (LSPs) was achieved by depositing a layer of continuous gold film onto the top surface of a matrix of randomly distributed gold nanoparticles (AuNPs) that were originally isolated on a glass substrate. Ultrafast spectroscopic response of such plasmonic nanostructures was investigated by femtosecond pump-probe detection technique. The transient-absorption data showed large redshift and broadening of the resonance spectrum of the conductively connected AuNPs with respect to the isolated ones. Such effects led to modulation on the evolution dynamics of LSPs in a transient transition spectral band. Making use of the temporal and spectral dislocation between the edges of transition band, we achieved much increased speed of the plasmonic optical switching effect.

5 illus, 19 ref

024190   TAN Y, CHU W, LIN J, FANG Z, LIAO Y, CHENG Y (Shanghai Institute of Optics and Fine Mechanics, Shanghai 201800,0, People’s Republic of China, Email: chuwei0818@qq.com) : Metal surface structuring with spatiotemporally focused femtosecond laser pulses. J Optics 2018, 20(1), 14010.

Femtosecond laser micromachining provides high precision and less thermal diffusion in surface structuring as a result of the ultrashort duration and ultrahigh peak intensity of the femtosecond laser pulses. To increase the throughput of surface patterning, the focal spot size can be expanded with loose focusing, which, however, could lead to nonlinear self-focusing of the pulses when the pulses propagate in air. We solve the problem by use of spatiotemporally focused femtosecond laser pulses for ablation of metal surfaces, which gives rise to improved surface quality as compared with that obtained with the conventional focusing scheme.

5 illus, 1 tbale, 23 ref

024189   TAO T, CHEN Q, FENG S, HU Y, ZHANG M, ZUO C (Nanjing Univ of Science and Technology, Jiangsu Province 210 094, Email: chenqian@njust.edu.cn) : High-precision real-time 3D shape measurement based on a quad-camera system. J Optics 2018, 20(1), 14009.

Phase-shifting profilometry (PSP) based 3D shape measurement is well established in various applications due to its high accuracy, simple implementation, and robustness to environmental illumination and surface texture. In PSP, higher depth resolution generally requires higher fringe density of projected patterns which, in turn, lead to severe phase ambiguities that must be solved with additional information from phase coding and/or geometric constraints. However, in order to guarantee the reliability of phase unwrapping, available techniques are usually accompanied by increased number of patterns, reduced amplitude of fringe, and complicated post-processing algorithms. In this work, we demonstrate that by using a quad-camera multi-view fringe projection system and carefully arranging the relative spatial positions between the cameras and the projector, it becomes possible to completely eliminate the phase ambiguities in conventional three-step PSP patterns with high-fringe-density without projecting any additional patterns or embedding any auxiliary signals. Benefiting from the position-optimized quad-camera system, stereo phase unwrapping can be efficiently and reliably performed by flexible phase consistency checks. Besides, redundant information of multiple phase consistency checks is fully used through a weighted phase difference scheme to further enhance the reliability of phase unwrapping. This paper explains the 3D measurement principle and the basic design of quad-camera system, and finally demonstrates that in a large measurement volume of 200 mm × 200 mm × 400 mm, the resultant dynamic 3D sensing system can realize real-time 3D reconstruction at 60 frames per second with a depth precision of 50 μm.

13 illus, 1 table, 45 ref

024188   HARTH A, GUO C, CHENG Y-C, LOSQUIN A, MIRANDA M, MIKAELSSON S, HEYL C M, PROCHNOW O, AHRENS J, MORGNER U, HUILLIER A L, ARNOLD C L (Physics Dep, Lund Univ, Lund, Sweden, Email: Cord.Arnold@fysik.lth.se) : Compact 200kHz HHG source driven by a few-cycle OPCPA. J Optics 2018, 20(1), 14007.

We present efficient high-order harmonic generation (HHG) based on a high-repetition rate, few-cycle, near infrared (NIR), carrier-envelope phase stable, optical parametric chirped pulse amplifier (OPCPA), emitting 6 fs pulses with 9 μJ pulse energy. In krypton, we reach conversion efficiencies from the NIR to the extreme ultraviolet (XUV) radiation pulse energy on the order of ∼10−6 with less than 3 μJ driving pulse energy. This is achieved by optimizing the OPCPA for a spatially and temporally clean pulse and by a specially designed highpressure gas target. In the future, the high efficiency of the HHG source will be beneficial for high-repetition rate two-colour (NIR-XUV) pump-probe experiments, where the available pulse energy from the laser has to be distributed economically between pump and probe pulses.

11 illus, 2 tables, 35 ref

024187   DENG W-M, CHEN X-D, ZHAO F-L, DONG J-W (Sun Yat-sen Univ, Guangzhou- 510275, People's Republic of China, Email: dongjwen@mail.sysu.edu.cn) : Transverse angular momentum in topological photonic crystals. J Optics 2018, 20(1), 14006.

Engineering local angular momentum of structured light fields in real space enables applications in many fields, in particular, the realization of unidirectional robust transport in topological photonic crystals with a non-trivial Berry vortex in momentum space. Here, we show transverse angular momentum modes in silicon topological photonic crystals when considering transverse electric polarization. Excited by a chiral external source with either transverse spin angular momentum or transverse phase vortex, robust light flow propagating along opposite directions is observed in several kinds of sharp-turn interfaces between two topologically-distinct silicon photonic crystals. A transverse orbital angular momentum mode with alternating phase vortex exists at the boundary of two such photonic crystals. In addition, unidirectional transport is robust to the working frequency even when the ring size or location of the pseudo-spin source varies in a certain range, leading to the superiority of the broadband photonic device. These findings enable one to make use of transverse angular momentum, a kind of degree of freedom, to achieve unidirectional robust transport in the telecom region and other potential applications in integrated photonic circuits, such as on-chip robust delay lines.

6 illus, 46 ref

024186   GRUPP A, BUDWEG A, FISCHER M P, ALLERBECK J, SOAVI G, LEITENSTORFER A, BRIDA D (Physics and Center for Applied Photonics Dep, Konstanz Univ, Konstanz-78457, Email: daniele.brida@uni-konstanz.de) : Broadly tunable ultrafast pump-probe system operating at multi-kHz repetition rate. J Optics 2018, 20(1), 14005.

Femtosecond systems based on ytterbium as active medium are ideal for driving ultrafast optical parametric amplifiers in a broad frequency range. The excellent stability of the source and the repetition rate tunable to up to hundreds of kHz allow for the implementation of an advanced two-color pump probe setup with the capability to achieve excellent signal-to-noise performances with sub-10 fs temporal resolution.

13 illus, 51 ref

024185   ZHANG W, WEI K, WANG H, MAO D, GAO F, HUANG L, MEI T, ZHAO J (Northwestern Polytechnical Univ, Xi’an 710072, , People's Republic of China, Email: zhangwd@nwpu.edu.cn) : Tunable-wavelength picosecond vortex generation in fiber and its application in frequency-doubled vortex. J Optics 2018, 20(1), 14004.

We present a method for tunable-wavelength picosecond vortex pulse generation by using an acoustically-induced fiber grating (AIFG). The AIFG-driven mode conversion characteristic was activated via a shear-mode piezoelectric transducer that excels in excitation efficiency of acoustic flexural wave and mechanical stability. The linearly-polarized ±1-order picosecond vortex pulse was experimentally generated via AIFG with a uniform coupling efficiency of ∼98.4% from the fundamental mode to the ±1-order vortex mode within the wavelength range 1540 nm ∼1560 nm. The topological charge and the linearly-polarized characteristic of the picosecond vortex pulse were verified by examination of the off-axial interference and the polarization angle-dependent intensity, respectively. Furthermore, the picosecond vortex pulse with wavelength tunability was input to a nonlinear BBO crystal to generate a frequency-doubled ±2-order vortex in the wavelength range 770 nm∼ 780 nm. This technology provides a convenient apparatus for generating a picosecond vortex pulse and the frequency-doubled vortex with wavelength tunability.

5 illus, 30 ref

024184   ISHII N, KANESHIMA K, KANAI T, WATANABE S, ITATANI S (The Univ of Tokyo, Chiba 277-8581, Japan, Email: shii@issp.u-tokyo.ac.jp) : Generation of sub-two-cycle millijoule infrared pulses in an optical parametric chirped-pulse amplifier and their application to soft x-ray absorption spectroscopy with high-flux high harmonics. J Optics 2018, 20(1), 14003.

An optical parametric chirped-pulse amplifier (OPCPA) based on bismuth triborate (BiB3O6, BIBO) crystals has been developed to deliver 1.5 mJ, 10.1 fs optical pulses around 1.6 μm with a repetition rate of 1 kHz and a stable carrier-envelope phase. The seed and pump pulses of the BIBO-based OPCPA are provided from two Ti:sapphire chirped-pulse amplification (CPA) systems. In both CPA systems, transmission gratings are used in the stretchers and compressors that result in a high throughput and robust operation without causing any thermal problem and optical damage. The seed pulses of the OPCPA are generated by intrapulse frequency mixing of a spectrally broadened continuum, temporally stretched to approximately 5 ps then, and amplified to more than 1.5 mJ. The amplified pulses are compressed in a fused silica block down to 10.1 fs. This BIBO-based OPCPA has been applied to high-flux high harmonic generation beyond the carbon K edge at 284 eV. The high-flux soft-x-ray continuum allows measuring the x-ray absorption near-edge structure of the carbon K edge within 2 min, which is shorter than a typical measurement time using synchrotron-based light sources. This laser-based table-top softx- ray source is a promising candidate for ultrafast soft x-ray spectroscopy with femtosecond to attosecond time resolution.

4 illus, 48 ref

024183   YANG L, LI P, LI Z (Physics Dep, Capital Normal Univ, Beijing 100 048, Email: zpli@cnu.edu.cn) : Emitting-polarization of surface plasmons coupling in metallic nanoantennas. J Optics 2018, 20(1), 14002.

Surface plasmons coupling of metallic nanoantennas plays an important role in light manipulation at the nanometer scale. In this work, we reveal surface plasmons coupling via emitting-polarization dependent measurements (under unpolarized excitation). By detecting the scattering at different emitting polarization angles, the surface plasmons coupling modes (resonance positions and preferential polarized orientations) can be well revealed, which can not only provide the polarization state of nanoantennas emission but also improve the peaks resolution of surface plasmon modes, especially when these modes are polarized orthogonally with each other. The emission polarization is greatly dependent on the surface plasmons coupling, and the coupled nanoantenna can work as a polarized light emitter at different resonant wavelengths. These results are of high importance for both the fundamental understanding of the interaction between light and plasmonic nanostructures, and the development of nanophotonic devices for light manipulation and sensing applications.

5 illus, 38 ref

024182   ZHANG Y, ZHANG B (Physics and Applied Physics Div, Nanyang Technological Univ, Singapore- 637 371, Email: blzhang@ntu.edu.sg) : Bending, splitting, compressing and expanding of electromagnetic waves in infinitely anisotropic media. J Optics 2018, 20(1), 14001.

High-efficiency diffraction-free manipulations of electromagnetic (EM) waves are fundamentally difficult to realize, though reflectionless wave bending or sub-diffraction-limited imaging has been realized separately in previous demonstrations. Recent advances in epsilon-near-zero and anisotropic epsilon-near-infinity metamaterials have provided unique possibilities to achieve reflectionless diffraction-free EM wave manipulations. Here, we propose bending, splitting, compressing and expanding of EM waves with infinitely anisotropic media that can be achieved without diffraction or reflection. The results are verified by numerical simulations. This work furthers the study of infinitely anisotropic media, and might find applications in high-efficiency interconnection of subwavelength photonic information.

4 tables, 22 ref

024181   MISHRA S, DIXIT P K, SELVAM T P, YAVALKAR S S, DESHPANDE D D (Radiological Physics and Advisory Div, Bhabha Atomic Research Centre, Mumbai - 400 09, Email: b.subwu@gmail.com) : Monte Carlo investigation of photon beam characteristics and its variation with incident electron beam parameters for indigenous medical linear accelerator. J Med Phys 2018, 43(1), 1 - 8.

A Monte Carlo model of a 6 MV medical linear accelerator (linac) unit built indigenously was developed using the BEAMnrc user code of the EGSnrc code system. The model was benchmarked against the measurements. Monte Carlo simulations were carried out for different incident electron beam parameters in the study.Simulation of indigenously developed linac unit has been carried out using the Monte Carlo based BEAMnrc user‑code of the EGSnrc code system. Using the model, percentage depth dose (PDD), and lateral dose profiles were studied using the DOSXYZnrc user code. To identify appropriate electron parameters, three different distributions of electron beam intensity were investigated. For each case, the kinetic energy of the incident electron was varied from 6 to 6.5 MeV (0.1 MeV increment). The calculated dose data were compared against the measurements using the PTW, Germany make RFA dosimetric system (water tank MP3‑M and 0.125 cm3 ion chamber).The best fit of incident electron beam parameter was found for the combination of beam energy of 6.2 MeV and circular Gaussian distributed source in X and Y with FWHM of 1.0 mm. PDD and beam profiles (along both X and Y directions) were calculated for the field sizes from 5 cm × 5 cm to 25 cm × 25 cm. The dose difference between the calculated and measured PDD and profile values were under 1 %, except for the penumbra region where the maximum deviation was found to be around 2 %. A Monte Carlo model of indigenous linac (6 MV) has been developed and benchmarked against the measured data.

12 illus, 3 tables, 34 ref

024180   ROY K, PAL P, GHOSH N K (Physics Dep, Kalyani Univ, Kalyani-741 235, Email: nanda.ku@rediffmail.com) : Signatures of next-nearest-neighbor (NNN) antiferromagnetic exchange interaction on high-Tc superconductivity within t-t'-J-J' model. Bull Pure Appl Sci- Sect D 2018, 37(D), 27-32.

The influence of the next-nearest-neighbor (NNN) antiferromagnetic interaction J' has been examined within t - t' - J - J' model in an exact technique. An 8-site square cluster is chosen as the representative of the system. The effect of the next-nearest-neighbor (NNN) antiferromagnetic interaction on various ground state properties such as electron-electron correlation, spin-spin correlation, effective hopping amplitude etc. has been studied. Temperature variation of the susceptibility shows that J' suppresses short range antiferromagnetic order. Applying periodic boundary conditions, the calculations have been extended beyond the 8-site limit.

4 illus, 24 ref

024179   SINGH S, CHOUDHARY P K (Physics Dep, N.N. Coll, Bihar- 844 126, Email: madanjeebrabu@gmail.com) : Symmetry breaking in one dimensional directional phtonic crystal wave guide. Bull Pure Appl Sci- Sect D 2018, 37(D), 23-6.

We have studied symmetry breaking in the one dimensional directional crystal wave guide that holds a single nonlinear defect positioned on the centre line of the waveguide. When only the monopole eigen mode of the defect cavity belongs to the propagation band of photonic crystal waveguide. There are varieties of nonlinear optical processes mostly related to a bistability of light transmission. Two dipole resonant modes of the single non-linear defect made from a Kerr medium. The degenerated dipole modes have opposite parities relative to injected even light mode propagating in the waveguide. For the linear cavity the light would be coupled with the even dipole mode only to give rise to Breit-Wigner resonant peak at the eigen frequency of the cavity. Nonlinear coupling between the dipole modes may cause excitation of both dipole modes. For equal phases, the symmetry is broken by the light intensity relative to mirror reflection.

1 illus, 12 ref

024178   KUMAR N, DAS A K L, KUMAR A (Physics Dep, P.R.D. Coll, Bihar- 843 313, Email: phylal69@gmail.com) : Electromagnetic characteristics of carbon nanotube based antennas. Bull Pure Appl Sci- Sect D 2018, 37(D), 19-22.

We have studied electromagnetic characteristics of carbon nanotube based antennas in different frequency regimes ranging from the microwave to visible. Analysis of the physical characteristics of carbon nanotube based integrated circuit elements, such as antennas, must follow the general principles of electrodynamics and must account for the peculiar dispersion properties of electrons in carbon nanotubes. A key element of the analysis is the formulation of the effective boundary conditions for electromagnetic field on the carbon nanotube surface. We have incorporated the presence of intershell tunneling in the effective boundary conditions, showing thereby that tunneling alters the effective boundary conditions significantly from the effective boundary conditions presented previously. In order to incorporate intershell tunneling in the effective boundary conditions, we have adopted a microscopic approach. We observed that intershell tunneling qualitatively changed the form of effective boundary conditions in a doublewall carbon nanotube in comparison to single wall carbon nanotubes. The surface current densities and the axial component of the electric field on the surfaces of different shells get coupled, which effect leaded to a generalized susceptibility that contained the mutual surface conductivities of both shells. The mutual surface condivities are caused by the tunneling. The existence of mutual condivities leaded to the appearance of electrostatic longitudinal waves in the spectra of a double wall carbon nanotube. Different types of guided waves in the double wall carbon nanotube arise from intershell tunneling. The dispersion characteristics of asymmetric like waves are strongly affected in the wide frequency range by intershell tunneling.

12 ref

024177   SINGH A R, GIRI A K, PANDEY H K (Physics Dep, J.P. Univ, Bihar- 841 301, Email: ashutosh.giri36@gmail.com) : Gravitational waves: A persual. Bull Pure Appl Sci- Sect D 2018, 37(D), 11 - 8.

This paper aims to provide an updated perusal of gravitational waves science besides providing a persuasive discussion on the causes of gravitational waves, its significance, gravitational detector, and the post LIGO regime.

1 illus, 6 ref

024176   SINHA G K, SINGH O P (Physics Univ Dep, J.P. Univ, Bihar- 841 301, Email: gautamkumarsinha@gmail.com) : Resonant features in bilayer nanoribbons in a single mode regime with a short range defect. Bull Pure Appl Sci- Sect D 2018, 37(D), 7-10.

We have studied resonant features in bilayer nanoribbon in a single mode regime with a short range defect. We have found the effect of edge disorder on the transport properties of a graphene nanoribbons and bilayer graphene nano-ribbons. We have developed an analytical approach that provides the exact results for the transmission coefficients of graphene nanoribbons. We have considered the case of bilayer graphene nanoribbons with zigzag and armchair edges. We have found that for the case of zigzag edge bilayer nanoribbon remain practically insensitive to the disorder situated close to the edges. This behavior is not related to the chiral edge state residing at the zigzg boundary, as this behavior persist into the few mode regime as well. It is related to the effective boundary condition at the zigzag edge which does not couple valleys, thus hindering the intervally scattering due to the edge disorder. The armchair edge mixes the valleys and it is found that the conductance of a graphene nanoribbons and a bilayer graphene nanoribbons is strongly affected by a small defect concentration. We have calculated the conductance in bilayer graphene nanoribbons with many defects on the basis of tight binding recursive Green’s function technique.

1 illus, 14 ref

024175   GUPTA B K, MISHRA M (Electronics Dep, DDU Gorakhpur Univ, Utter Pradesh-273 009, Email: manish.ddu1976@gmail.com) : Comparative study of I_on/I_off ratio of silicon nanowire transistor (SNWT) with planner MOSFET. Bull Pure Appl Sci- Sect D 2018, 37(D), 1 - 6.

In this paper, a general approach, that considers both electrostatic integrity and quantum confinement, so called the “EQ approach”, to compare the device performance of nanoscale Si FETs with various gate geometry configurations, i.e., planar MOSFETs versus SNWTs, is proposed. A better gate control, e.g., a better sub threshold swing and a higher ON-OFF current ratio is reported. This approach is based on the use of L_Qvs. L_E plot, where L_Q is the quantum confinement length, and L_E denotes the electrostatic scale length.

3 illus, 14 ref

024174   KUMAR K V, REDDY E K (Mathematics Dep, JNTUA Coll of Engineering, Andhra Pradesh- 515 002., Email: gotovijay007@gmail.com) : Magneto-convective fluid flow past an exponentially accelerated vertical porous plate in the presence of thermal diffusion. Bull Pure Appl Sci- Sect E 2018, 37E(1), 230-44.

A theoretical analysis is performed to analyze the characteristics of an unsteady free convective, radiative, chemically reactive, viscous, incompressible and electrically conducting fluid past an exponentially accelerated vertical porous plate in the presence of heat source and Soret effects. The set of non-dimensional governing equations along with boundary conditions are solved numerically by applying finite difference method. The effect of various physical parameters on flow quantities are studied with the help of graphs. For the physical interest, the variations in skin friction, Nusselt number and Sherwood number are also studied through tables. The novelty of this study is the consideration of exponentially varying temperature as well as concentration along with the exponentially accelerated vertical plate.

10 illus, 3 tables, 35 ref

024173   DAVIS S (Research Foundation of Southern California, CA- 92039, Email: sbdavis@resfdnsca.org) : A condition on the masses of composite particles. Bull Pure Appl Sci- Sect E 2018, 37E(1), 208-22.

Based on the recent formulation of the standard model with the spinor space given by a direct sum of tensor products of modules isomorphic to division algebras, these algebras are used to derive an expression for masses of elementary particles. It is shown that the formula derived for the tensor product of states is consistent with the Lagrangian model of composite particles.

024172   OBULESU M, PRASAD R S (Mathematics Dep, Sri Krishnadevaraya Univ, Andhra Pradesh-515 003, Email: mopuriobulesu1982@gmail.com) : Radiation absorption effect on MHD dissipative fluid past a vertical porous plate embedded in porous media. Bull Pure Appl Sci- Sect E 2018, 37E(1), 184-99.

In this manuscript, an attempt is made to study the radiation absorption effect on MHD dissipative fluid past a vertical porous plate embedded in porous media; under the influence of a uniform magnetic field applied normal to the surface is studied. The governing equations are solved analytically using a regular perturbation technique. The expression for velocity, temperature and concentration fields are obtained with the aid of these, the expressions for the coefficient of skin friction, the rate of heat transfer in the form of Nusselt number and the rate of mass transfer in the form of Sherwood number are derived. Finally the effect of variation of physical parameters on the flow quantities is studied with the help of graphs and tables. It is observed that the velocity and concentration increase during a generative reaction and decrease in a destructive reaction. The same is observed to be true for the behaviour of the fluid temperature. The presence of magnetic field and radiation diminishes the velocity and also the temperature.

11 illus, 3 tables, 31 ref

024171   SUNEETHA T, SAILAKUMARI A (Mathematics Dep, Jawaharlal Nehru Technological Univ, Andhra Pradesh-515 002, Email: saiyasmitha@gmail.com) : Magneto hydrodynamic convective double diffusive fluid flow past a vertical plate with varying temperature and concentration. Bull Pure Appl Sci- Sect E 2018, 37E(1), 137-51.

This manuscript presents the influence of variable boundary of temperature and concentration of a double diffusive unsteady MHD natural convection heat and mass transfer flow past an accelerated vertical porous plate in the presence of thermal radiation and chemical reaction. The dimensionless governing equations along with the relevant boundary conditions are solved numerically by using finite difference method. The effects of pertinent physical parameters on velocity, temperature and concentration are discussed with the help of graphical representations. With the aid of the expression of velocity, concentration and temperature distributions, variations in skin friction, the rate of heat transfer in the form of Nusselt number and the rate of mass transfer in the form of Sherwood number are also analyzed. The velocity decreases with an increase in magnetic parameters and porosity parameter. The temperature increases with an increase in the Dufour number. Concentration falls down under the influence of Schmidt number and chemical reaction.

12 illus, 3 tables, 33 ref

024170   REDDY S H, RAJU M C, REDDY P C (Humanities & Sciences Dep, Annamacharya Institute of Technology and Sciences, Andhra Pradesh- 516 126, Email: mcrmaths@gmail.com) : Joule heating and radiation absorption effects on MHD convective and chemically reactive flow past a porous plate. Bull Pure Appl Sci- Sect E 2018, 37E(1), 117-36.

The aim of this study is to analyze the effects of Joule heating and radiation absorption on MHD convective and chemically reactive flow past an inclined porous plate in the presence of heat source and thermal diffusion. The non-linear partial differential equations that govern the fluid flow have been transformed into a two-point boundary value problem using similarity variables and then solved numerically by fourth order Runge–Kutta method with shooting technique. Graphical results are discussed for non-dimensional velocity, temperature and concentration profiles while numerical values of the skin friction, Nusselt number and Sherwood number are presented in tabular form for various values of parameters controlling the flow system. The present study is compared with the previous literature and found to be in good agreement. The novelty of this work is the consideration of Ohmic heating, radiation absorption and thermal diffusion.

25 illus, 26 ref

024169   CHAND K, THAKUR N (Mathematics and Statistics Dep, Himachal Pradesh Univ, Shimla- 171 005, Email: nidhithakurmaths55@gmail.com) : Effects of chemical reaction and heat absorption on hydromagnetic flow past a moving plate through porous medium with ramped wall temperature in the presence of hall current and thermal radiation. Bull Pure Appl Sci- Sect E 2018, 37E(1), 21-40.

This paper deals with the study of effects of chemical reaction and heat absorption on an unsteady free convective flow of a viscous, incompressible, electrically conducting and optically thin fluid past an infinite vertical moving plate through porous medium with ramped wall temperature in the presence of Hall current and thermal radiation. The governing equations are converted into non-dimensional form and then solved by using the Laplace transform technique. The expressions are obtained for fluid velocity, fluid temperature, species concentration, skin friction, Nusselt number and Sherwood numbers. Effects of pertinent flow parameters are presented graphically and discussed quantitatively. It is found that the increase in chemical reaction and heat absorption parameters contribute in thinning the momentum and thermal boundary layers.

12 illus, 1 table, 19 ref

024168   BAIJU V, DEVADATHAN D, RAVEENDRAN R (Physics Dep, Sree Narayana Coll, Kollam- 691 001, Email: baijuvkollam@gmail.com) : Photocatalytic degradation of an acidic dye and a basic dye using heterostructured photocatalyst. Bull Pure Appl Sci-Sect C 2018, 37C(1), 36-42.

Most of the natural resources of drinking water are found to be contaminated with various toxic materials. One of the most relevant pollutants is organic dyes. Photocatalysis is a promising green technology for the removal of dyes. In the present work heterostructured NiO/ZnO nanocomposite was prepared using co–precipitation method, analyzed using XRD, SEM and UV/Vis spectroscopy. For comparison purpose NiO was also prepared. Comparison of XRD’s of metal oxides with JCPDS confirmed the formation of heterojunctions. UV/Vis absorption studies confirmed the shift of the optical absorption towards the visible region. The photocatalytic degradations of dyes namely Malachite Green, a basic and Congo Red, an acidic dye were carried out using the prepared composite. Factors affecting photocatalytic degradation like effect of contact time, amount of photocatalyst and dye concentration were also investigated. Results suggested an increase in degradation efficiency in the case of heterojunctions nanocomposite as compared to individual metal oxide.

6 illus, 2 tables, 13 ref

024167   VIDYA S, THOMAS J K (Physics Dep, Sree Narayana Coll, Kollam- 691 001, Email: vidyaasnair@gmail.com) : Optical and dielectric investigations of nano crystalline scheelite A_0.5B_0.5 (A=B=Ba, Sr and Ca). Bull Pure Appl Sci-Sect C 2018, 37C(1), 27-35.

The synthesis of nanocrystalline A_0.5B_0.5MoO₄ by an auto-igniting combustion technique is reported. The structural characterization done by X–ray diffraction, Fourier transform Raman spectroscopy and infrared spectroscopy reveals that the as-prepared powder itself is phase pure with tetragonal structure. The particle size determined from Transmission electron microscopy are in the range 23–25 nm. The optical band gap determined show that the compounds are wide bandgap semiconductors. The photoluminescence spectrum of A_0.5B _0.5 MoO₄ shows green emission, associated with the perfect order and crystallinity of the sample. All the samples are sintered at a temperature less than 875°C. The dielectric constant and loss factor of the samples are measured at radio frequency range and its variation with temperature is also studied. The effect of change in composition of A²⁺ site of scheelite AMO₄ compounds comparative are also presented. The experimental results show that nano A_0.5B_0.5MoO₄ is an excellent luminescent material and also a promising ‘Low temperature Co–fired Ceramic. Also it is inferred that we can fine tune both optical and dielectric properties to desired values according to our requirements by adjusting the cationic stoichiometric ratio in [AO₈] octahedron.

9 illus, 2 tables, 27 ref

023384   ZHANG X, JIANG J, LIU K, YU Z, FENG M , CHEN W, LIU T (Coll of Precision Instrument & Opto-electronics Engineering, Tianjin Univ, Tianjin- 300 072, Email: jiangjfjxu@tju.edu.cn) : Suppressing the crosstalk between racetrack resonators by grating assisted couplers for WDM sensing. J Optics 2017, 19(12), 125801.

We proposed a uniform racetrack resonators based sensor for bio-chemical WDM sensing. The sensing channels are assigned by grating assisted contra-directional couplers. Each resonator only occupies one sensing channel. The crosstalk between sensing channels can be suppressed by aligning the center coupling wavelength of one resonator with the weak coupling wavelength of the others. Based on the simulation results obtained from transfer matrix method, the sensing channel gap can be reduced down to 2 FSRs (?1.5 nm) of the resonator. The total crosstalk can be as low as 2.5 × 10^?2 dB in a sensor with 23 channels covering the whole C band. This sensor with high throughput will be very important for analyzing a wide range of analytes, such as organic compounds or biological materials.

7 illus, 26 ref

023383   KLEINER V, RUDNITSKY A, ZALEVSKY Z (Bar-Ilan Univ, Israel, Email: zeev.zalevsky@biu.ac.il) : Direct-phase and amplitude digitalization based on free-space interferometry. J Optics 2017, 19(12), 125704.

A novel ADC configuration that can be characterized as a photonic-domain flash analog-to-digital convertor operating based upon free-space interferometry is proposed and analysed. The structure can be used as the front-end of a coherent receiver as well as for other applications. Two configurations are considered: the first, ‘direct free-space interference’, allows simultaneous measuring of the optical phase and amplitude; the second, ‘extraction of the ac component of interference by means of pixel-by-pixel balanced photodetection’, allows only phase digitization but with significantly higher sensitivity. For both proposed configurations, we present Monte Carlo estimations of the performance limitations, due to optical noise and photo-current noise, at sampling rates of 60 giga-samples per second. In terms of bit resolution, we simulated multiple cases with growing complexity of up to 4 bits for the amplitude and up to 6 bits for the phase. The simulations show that the digitization errors in the optical domain can be reduced to levels close to the quantization noise limits. Preliminary experimental results validate the fundamentals of the proposed idea.

17 illus, 3 tables, 18 ref

023382   FENG W, GU Z, LIN Q, SANG J (Coll of Science, Univ of Shanghai for Science and Technology, Shanghai- 200 093, Email: wenbinfeng_optics@163.com) : Simulation of novel intensity modulated cascaded coated LPFG sensor basedon PMTP. J Optics 2017, 19(12), 125703.

This paper presents a novel intensity modulated cascaded long-period fiber grating (CLPFG) sensor which is cascaded by two same coated long-period fiber gratings (LPFGs) operating at the phasematching turning point (PMTP). The sensor combines the high sensitivity of LPFG operating at PMTP and the narrow bandwidth of interference attenuation band of CLPFG, so a higher response to small change of the surrounding refractive index (SRI) can be obtained by intensity modulation. Based on the coupled-mode theory, the grating parameters of the PMTP of a middle odd order cladding mode of a single LPFG are calculated. Then this two same LPFGs are cascaded into a CLPFG, and the optical transmission spectrum of the CLPFG is calculated by transfer matrix method. A resonant wavelength of a special interference attenuation band whose intensity has the highest response to SRI, is selected form CLPFG’s spectrum, and setting the resonant wavelength as the operating wavelength of the sensor. Furthermore, the simulation results show that the resolution of SRI of this CLPFG is available to 1.97 × 10^?9 by optimizing the film optical parameters, which is about three orders of magnitude higher than coated dual-peak LPFG and cascaded LPFG sensors. It is noteworthy that the sensor is also sensitive to the refractive index of coat, so that the sensor is expected to be applied to detections of gas, PH value, humidity and so on, in the future.

8 illus, 1 table, 27 ref

023381   KUPFERMAN J, ARNON S (Electrical and Computer Engineering Dep, Ben-Gurion Univ of the Negev, Beer-Sheva, Israel, Email: shlomi@bgu.ac.il) : Decision algorithm for data center vortex beam receiver. J Optics 2017, 19(12), 125702.

We present a new scheme for a vortex beam communications system which exploits the radial component p of Laguerre–Gauss modes in addition to the azimuthal component l generally used. We derive a new encoding algorithm which makes use of the spatial distribution of intensity to create an alphabet dictionary for communication. We suggest an application of the scheme as part of an optical wireless link for intra data center communication. We investigate the probability of error in decoding, for several detector options.

6 illus, 1 table, 37 ref

023380   XIA J, CHANG C, CHEN Z, ZHU Z, ZENG T, LIANG P, DING J (National Laboratory of Solid State Microstructures and School of Physi, Nanjing Univ, Nanjing- 210 093, Email: jpding@nju.edu.cn) : Pixel-addressable phase calibration of spatial light modulators: a common-path phase-shifting interferometric microscopy approach. J Optics 2017, 19(12), 125701.

As spatial light modulators (SLMs) are becoming flexible and the preferred device for light steering, the SLM’s modulation calibration still remains challenging. No pixel-addressable measurement of the SLM has yet been practically implemented. We present a quantitative phase measurement and calibration method for a parallel aligned liquid crystal spatial light modulator (PAL-SLM) based on Pancharatnam phase-shifting interferometric microscopy. The pixel-wise phase of SLM can be detected from microscopic interference pattern formed from two orthogonally polarized light waves reflected off the PAL-SLM. The wave phase is modulated or non-modulated depending on its polarization direction parallel or orthogonal to the liquid crystal director. Owing to self-referencing common-path interferometric microscopic imaging, the proposed method is quite robust against environmental disturbance and enables a high-precision pixel-wise characterization of SLM.

9 illus, 1 table, 33 ref

023379   YANG M, WU Y, SHENG X, REN K F (School of Information and Elecytonics, Beijing Institute of Technology, Beijing- 100 081, Email: fang.ren@coria.fr) : Computational study of scattering of a zero order Bessel beam by large non spherical homogeneous particles with the multilevel fast multiple algorithm. J Optics 2017, 19(12), 125606.

Computation of scattering of shaped beams by large nonspherical particles is a challenge in both optics and electromagnetics domains since it concerns many research fields. In this paper, we report our new progress in the numerical computation of the scattering diagrams. Our algorithm permits to calculate the scattering of a particle of size as large as 110 wavelengths or 700 in size parameter. The particle can be transparent or absorbing of arbitrary shape, smooth or with a sharp surface, such as the Chebyshev particles or ice crystals. To illustrate the capacity of the algorithm, a zero order Bessel beam is taken as the incident beam, and the scattering of ellipsoidal particles and Chebyshev particles are taken as examples. Some special phenomena have been revealed and examined. The scattering problem is formulated with the combined tangential formulation and solved iteratively with the aid of the multilevel fast multipole algorithm, which is well parallelized with the message passing interface on the distributed memory computer platform using the hybrid partitioning strategy. The numerical predictions are compared with the results of the rigorous method for a spherical particle to validate the accuracy of the approach. The scattering diagrams of large ellipsoidal particles with various parameters are examined. The effect of aspect ratios, as well as half-cone angle of the incident zero-order Bessel beam and the off-axis distance on scattered intensity, is studied. Scattering by asymmetry Chebyshev particle with size parameter larger than 700 is also given to show the capability of the method for computing scattering by arbitrary shaped particles.

16 illus, 46 ref

023378   LI S, WANG Y, WU W, LIANG Y (Institute of Modern Optics, Nankai Univ, Tianjin- 300 350, Email: ymliang@nankai.edu.cn) : Predictive searching algorithm for fourierptychography. J Optics 2017, 19(12), 125605.

By capturing a set of low-resolution images under different illumination angles and stitching them together in the Fourier domain, Fourier ptychography (FP) is capable of providing high resolution image with large field of view. Despite its validity, long acquisition time limits its real-time application. We proposed an incomplete sampling scheme in this paper, termed the predictive searching algorithm to shorten the acquisition and recovery time. Informative subregions of the sample’s spectrum are searched and the corresponding images of the most informative directions are captured for spectrum expansion. Its effectiveness is validated by both simulated and experimental results, whose data requirement is reduced by ?64% to ?90% without sacrificing image reconstruction quality compared with the conventional FP method.

10 illus, 19 ref

023377   VAN L C, ANUSZKIEWICZ A, RAMANIUK A, KASZTELANIC R, XUAN K D, LONG V C, TRIPPENBACH M, BUCZYNSKI R (Physics Dep, Vinh Univ, Vietnam, Email: alicja.anuszkiewicz@itme.edu.pl) : Supercontinuum generation in photonic crystal fibres with core filled with toluene. J Optics 2017, 19(12), 125604.

A photonic crystal fibre with hollow core filled with toluene is considered as a new system for coherent supercontinuum generation. The dispersion characteristics are studied for various geometrical parameters of photonic crystal fibres. Two structures with lattice constant 2 ?m, filling factors d/? 0.3 and 0.35 and toluene core of diameters of 3.34 and 3.23 ?m have flat dispersion in the near infrared range. The structure with d/? = 0.3 has all-normal dispersion characteristics in whole near-infrared wavelength range, while the second structure (d/? = 0.35) has anomalous dispersion for wavelengths longer than 1.5 ?m. Although confinement losses in the considered structures are as high as 0.4 dB cm^?1 , we show that the generation of coherent supercontinuum in the range 1.0–1.7 ?m with the pulse energy conversion of 16% is feasible in 4 cm long fibre samples with standard fibre femtosecond lasers.

9 illus, 1 table, 34 ref

023376   STOCKSCHLADER P, HENTSCHEL M (Institute for Physics, Technische Universität, Ilmenau, Germany, Email: martina.hentschel@tu-ilmenau.de) : Consequences of a wave-correction extended ray dynamics for integrable and chaotic optical microcavities. J Optics 2017, 19(12), 125603.

Ray optics have proven to be an effcient and versatile tool to describe dielectric optical microcavities and their far-field emission based on the principle of ray-wave correspondence. Whereas often the well-known ray-optics at planar interfaces yields reasonable results, semiclassically and boundary-curvature induced corrections will become more important as the cavity size is further reduced. In this paper, we summarize the various ray optics descriptions of optical microresonators, in addition paying special attention to the differences that arise between chaotic versus non-chaotic (integrable or nearly integrable) resonator geometries, respectively. Whereas the far-field pattern in the chaotic case is known to be determined by the overlap of the unstable manifold with the leaky region, it results from the emission of trajectories with the smallest nonzero decay rates in the non-chaotic situation. We present an enhanced ray optical description, extended by wave-inspired (semiclassical) corrections, and discuss their consequences for the ray dynamics. In particular, we find clear indications for the presence of attractors resulting from the non-Hamiltonian character of the extended ray dynamics in phase space. We illustrate their impact on the far-field emission and show that it can considerably differ from the conventional ray description result.

6 illus, 43 ref

023375   YU Z, LU Y, HU X, MENG Z (Academy of Ocean Science and Engineering, National Univ of Defense Technology, Changsha- 410 073, Email: shangshan_101@126.com) : Polarization dependence of the noise of phase measurement based on phase sensitive OTDR. J Optics 2017, 19(12), 125602.

A phase-sensitive optical time-domain reflectometry (?-OTDR) implements high-sensitivity vibration measurement by measuring vibration induced phase change of Rayleigh scattering from the sensing fiber. Minimum detectable vibration of a ?-OTDR is limited by the noise of the phase measurement. In this paper, polarization dependence of the noise of phase measurement in a ?-OTDR is investigated theoretically and experimentally. The correspondence between the intensity of Rayleigh scattering and the polarization state of the probe pulse in a ?-OTDR is analyzed considering inner interference of coherent Rayleigh light scattered within pulse duration and polarization dependence of propagation constant. Experiments are performed and the results confirm the predictions of the theoretical analysis. This study is essential for acquiring insight into polarization dependence of vibration measurement based on a ?-OTDR, and would provide a feasible method to eliminate the effect of polarization fading and optimize the minimum detectable vibration of a ?-OTDR.

5 illus, 18 ref

023374   YANG Z, VORONTSOV M A (Electro-Optics and Photonics Dep, Univ of Dayton, Dayton, USA, Email: mvorontsov1@udayton.edu) : Impact of atmospheric turbulence and refractivity on the modulation transfer function of incoherent imaging system. J Optics 2017, 19(12), 125601.

The joint impact of atmospheric refraction and turbulence effects on the modulation transfer function (MTF) of an incoherent imaging system is analyzed using numerical simulations based on the brightness function technique. Atmospheric refractivity is described by a combination of the standard MUSA76 and inverse temperature layer (ITL) models, and atmospheric turbulence effects are accounted for using the classical Kolmogorov turbulence framework. We show that ITL-induced refractivity located in the vicinity of an air volume essential for image formation can create strongly spatially anisotropic phase aberrations, which may significantly impact imaging system performance. Numerical analysis demonstrates that these phase aberrations may change the image size, and cause spatial frequency shifts in observed images of horizontally oriented sine-patterns. Numerical simulations show the that combined effects of atmospheric turbulence and ITL-induced refractivity cause the MTF to be a nonlinear function that is dependent on the imaging system characteristics, propagation path geometry, and atmospheric turbulence and ITL-induced refractivity parameters.

9 illus, 26 ref

023373   HOGGARTH R A, FRANCIS-JONES R J A, MOSLEY P J (Centre for Photonics and Photonic Materials, Univ of Bath, Bath, U K, Email: r.j.a.francis-jones@bath.ac.uk) : Resource-efficient fibre-integrated temporal multiplexing of heralded single photons. J Optics 2017, 19(12), 125503.

We present a multiplexed single photon source that re-synchronises heralded single photons generated by four-wave mixing in photonic crystal fibre using a fibre delay loop controlled by a single switch. By combining the probabilities of generating heralded single photons on four consecutive pump pulses we obtain an enhancement of the per-bin single-photon delivery probability. Our source demonstrates a way in which single-photon source multiplexing may be carried out with minimised resource overhead while retaining the benefits of a robust and alignment-free platform.

5 illus,1 table, 38 ref

023372   ZHOU M, LIU H, WANG Z , HUANG N, HAN J (State Key Laboratory of Transient Optics and Photonics, Xi’an Institute of Optics and Precision Mechanics, Xi’an- 710 119, Email: liuhongjun@opt.ac.cn) : Temporal imaging based on four-wave mixing in slow-light photonic crystal waveguide. J Optics 2017, 19(12), 125502.

We have proposed a temporal imaging system based on four-wave mixing (FWM) in the dispersion engineered slow-light photonic crystal waveguide (PCW). Dispersion relations of the modified PCW are calculated through the 3D plane wave expansion method. Time lens is demonstrated by solving the couple-mode equations describing the FWM process inside the PCW directly. Intensity and phase evolutions of the signal, pump and idler waves during the FWM process are calculated to investigate temporal imaging. Meanwhile, temporal magnifications with different magnification factors are realized by tuning the total dispersion of the input signals. Furthermore, influences of dispersion and free-carrier effects inside PCW on the temporal imaging performance are analyzed. The simulation results show the capability to realize temporal imaging system based on the FWM process in slow-light engineered PCW.

7 illus, 23 ref

023371   LIU Y, WANG C, LUO D, YANG C, LI J, GE L, PAN Y, LI W (State Key Laboratory of Precision Spectroscopy, East China Normal Univ, Shanghai- 200 062, Email: wxli@phy.ecnu.edu.cn) : Generation of 70 fs broadband pulses in a hybrid nonlinear amplification system with mode-locked Yb: YAG ceramic oscillator. J Optics 2017, 19(12), 125501.

We demonstrate the passively mode-locked laser performances of bulk Yb:YAG ceramic prepared by non-aqueous tape casting, which generates initial pulses in temporal width of 3 ps and spectrum width of 3 nm without intra-cavity dispersion management. The ceramic laser is further used as seeding oscillator in a fiber nonlinear amplification system, where ultrashort pulses in maximum output power of ?100 W and pulse duration of 70 fs are achieved. Moreover, the laser spectrum is broadened to be ?41 nm due to self-phase modulation effects in the gain fiber, overcoming the narrow spectrum limitations of ceramic materials. Our approach opens a new avenue for power-scaling and spectrum-expanding of femtosecond ceramic lasers.

5 illus, 24 ref

023370   SAMLAN C T, VISWANATHAN N K (School of Physics, Univ of Hyderabad, Hyderabad- 500 046, Email: nirmalsp@uohyd.ac.in) : Geometric phase topology in weak measurement. J Optics 2017, 19(12), 125401.

The geometric phase visualization proposed by Bhandari (R Bhandari 1997 Phys. Rep. 281 1–64) in the ellipticity-ellipse orientation basis of the polarization ellipse of light is implemented to understand the geometric aspects of weak measurement. The weak interaction of a preselected state, acheived via spin-Hall effect of light (SHEL), results in a spread in the polarization ellipticity (?) or ellipse orientation (?) depending on the resulting spatial or angular shift, respectively. The post-selection leads to the projection of the ? spread in the complementary ? basis results in the appearance of a geometric phase with helical phase topology in the ? ? ? parameter space. By representing the weak measurement on the Poincaré sphere and using Jones calculus, the complex weak value and the geometric phase topology are obtained. This deeper understanding of the weak measurement process enabled us to explore the techniques’ capabilities maximally, as demonstrated via SHEL in two examples—external reflection at glass-air interface and transmission through a tilted half-wave plate.

8 illus, 43 ref

023369   BIALYNICKI-BIRULA I, BIALYNICKA-BIRULA Z (Center for Theoretical Physics, Polish Academy of Sciences, Warsaw, Poland, Email: birula@cft.edu.pl) : Quantum-mechanical description of optical beams. J Optics 2017, 19(12), 125201.

The quantum mechanics of photons is derived from the theory of representations of the Poincaré group developed by Wigner. This theory places helicity as the most fundamental property; angular momentum and polarization are secondary characteristics. The properties of light beams are shown to be fully determined by the quantum states of the photons. Beam polarization is explained as the freedom to chose an arbitrary combination of the helicity states. The quantum mechanics of photons enables one to give a precise meaning to the concept of wave?particle duality.

28 ref

023368   LI A, FORATI E, SIEVENPIPER D (Electrical and Computer Engineering Dep, Univ of California San Diego, USA, Email: dsievenpiper@ucsd.edu) : Study of the electric field enhancement in resonant metasurfaces. J Optics 2017, 19(12), 125104.

The electric field properties (distribution and enhancement) of high impedance surfaces under radiation are studied. It is shown that the electric field enhancement at the gap between metal plates has a linear relation with a geometrical factor and is independent of the resonator quality factor. Conditions under which the metasurface can act as an efficient optical absorber are also studied. At the end, wavelengths around 800 nm are suggested for silver (plasmonic) resonators at optical frequencies to maximize the electric field enhancement.

8 illus, 2 tables, 39 ref

023367   ZENG J, LUK T S, GAO J, YANG X (Mechanical and Aerospace Engineering Dep, Missouri Univ of Science and Technology, Rolla, USA, Email: gaojie@mst.edu) : Structured light generation by magnetic metamaterial half-wave plates at visible wavelength. J Optics 2017, 19(12), 125103.

Metamaterial or metasurface unit cells functioning as half-wave plates play an essential role for realizing ideal Pancharatnam–Berry phase optical elements capable of tailoring light phase and polarization as desired. Complex light beam manipulation through these metamaterials or metasurfaces unveils new dimensions of light–matter interactions for many advances in diffraction engineering, beam shaping, structuring light, and holography. However, the realization of metamaterial or metasurface half-wave plates in visible spectrum range is still challenging mainly due to its specific requirements of strong phase anisotropy with amplitude isotropy in subwavelength scale. Here, we propose magnetic metamaterial structures which can simultaneously exploit the electric field and magnetic field of light for achieving the nanoscale half-wave plates at visible wavelength. We design and demonstrate the magnetic metamaterial half-wave plates in linear grating patterns with high polarization conversion purity in a deep subwavelength thickness. Then, we characterize the equivalent magnetic metamaterial half-wave plates in cylindrical coordinate as concentric-ring grating patterns, which act like an azimuthal half-wave plate and accordingly exhibit spatially inhomogeneous polarization and phase manipulations including spin-to-orbital angular momentum conversion and vector beam generation. Our results show potentials for realizing on-chip beam converters, compact holograms, and many other metamaterial devices for structured light beam generation, polarization control, and wavefront manipulation.

7 illus, 52 ref

023366   KURILKINA S N , PETROV N S , ZIMIN A B, BELYI V N (Institute of Physics, NAS of Belarus, Minsk, Belarus, Email: s.kurilkina@ifanbel.bas-net.by) : Special inhomogeneous electromagnetic waves in hyperbolic metamaterials. J Optics 2017, 19(12), 125102.

Herein, it is shown that under conditions of total internal reflection of plane homogeneous electromagnetic waves at the interface of a hyperbolic metamaterial (HMM) and an ordinary isotropic medium, special inhomogeneous electromagnetic waves are excited in certain circumstances near the surface of the metamaterial and their amplitude changes with distance according to the non-exponential law. The existence conditions for such waves are established for the case when the optical axis is located within the interface plane and forms an angle with the plane of incidence. The energy flux and density of energy of special inhomogeneous waves in a HMM are determined.

8 illus, 43 ref

023365   LU H , ZHANG K ,KANG X, ZHANG J, XIA S , SHEN K, ZHANG Z, ZHANG X (Engineering Laboratory for Optoelectronic Technology and Advanced Manu, Henan Normal Univ, Xinxiang- 453 007, Email: luhai123@gmail.com) : Abnormal mode splitting in photonic crystals micro-cavity containing highly dispersive metamaterials. J Optics 2017, 19(12), 125101.

We theoretically study abnormal mode splitting in a one-dimensional photonic crystals (PhCs) micro-cavity composed of highly dispersive metamaterials and dielectric. In particular, the abnormal split peaks can be posited in normal and anomalous dispersion regions, respectively. The normal split modes in conventional all-dielectric PhCs are always blue shifted owing to the propagating phases in two kinds of dielectrics decrease with incident angle. Here, based on the phase variation compensation between anomalous dispersion metamaterials and the dielectric, the dispersion of the split mode can be offset and thus red shift abnormal modes splitting can be realized. Moreover, such abnormal splitting modes can be either tuned by the optical properties of the PhCs, but also by the dispersion characteristics of the material. The abnormal splitting modes will possess potential applications for angle-tuned etalon filters, angle-dependent optical sensor, nonlinear optical devices, and so on.

6 illus, 31 ref

023364   ZHANG C , BAI R , GU X , JIN Y , ZHANG Y Q , JIN X R , ZHANG S, LEE Y (Physics Dep, Yanbian Univ, Jilin- 133 002, Email: yqzhang@ybu.edu.cn) : Unidirectional reflectionless phenomenon in ultra compact non-Hermitian plasmonic waveguide system based on phase coupling. J Optics 2017, 19(12), 125005.

Unidirectional reflectionless phenomenon is theoretically investigated based on phase coupling in an ultracompact non-Hermitian plasmonic waveguide system, which consists of two metalinsulator-metal (MIM) stub resonators side coupled to a MIM plasmonic waveguide. By appropriately tuning the phase difference between two stub resonators, the reflectivity for forward direction reaches to 0.91 and backward direction is close to 0 at the exception point (EP), while the backward absorption reaches to 0.98 and the forward absorption is close to 0.05. Hence, the unidirectional coherent perfect absorption (CPA) is realized at the vicinity of EP. This work will provide potential applications in the filter, sensor, plasmonic diode-like device, and so on.

4 illus, 41 ref

023363   SANG-NOURPOUR N, LAVOIE B R, KHERADMAND R, REZAEI M, SANDERS B C (Research Institute for Applied Physics and Astronomy, Univ of Tabriz, Iran, Email: nafiseh.sangnourpour@ucalgary.ca) : Characterization of surface-plasmon polaritons at lossy interfaces. J Optics 2017, 19(12), 125004.

We characterize surface-plasmon polaritons at lossy planar interfaces between one dispersive and one nondispersive linear isotropic homogeneous media, i.e. materials or metamaterials. Specifically, we solve Maxwell’s equations to obtain strict bounds for the permittivity and permeability of these media, such that satisfying these bounds implies surface-plasmon polaritons successfully propagate at the interface, and violation of the bounds impedes propagation, i.e. the field delocalizes from the surface into the bulk. Our characterization of surface-plasmon polaritons is valuable for checking the viability of a proposed application, and, as an example, we employ our method to falsify a previous prediction that surface-plasmon propagation through a surface of a double-negative refractive index medium occurs for any permittivity and permeability; instead, we show that propagation can occur only for certain medium parameters.

5 illus, 40 ref