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Crystalline sponges have made “crystallography without crystals” possible and have currently receive much attention, but it is difficult to apply them directly because of the tedious activation procedures. Therefore, it is important to prepare crystalline sponges that are highly stable and easy to operate. In this work, a new carbazole metal organic framework (CMOF) was synthesized and characterized via NMR, MS and X-ray diffraction analyses. The CMOF could directly capture liquids G1–G3, solids G4 and G5 in a THF solution, a mixture of G2 and G5, and monomers and mixed enantiomeric molecules G6–G9 without the need for activation. Furthermore, the CMOF could be used to identify the products from phytochemical isolation [cinnamaldehyde (G10)], organic synthesis [benzyl 2-hydroxybenzoate (G11)] and biosynthesis [veratryl alcohol (G12)] and monitor chemical reactions [acetylation of 4-allyl-2-methoxyphenol (G13) to 4-allyl-2-methoxyphenyl acetate (G14)]. The guests bound to the CMOF via five different modes (I–V). Thus, this work reports a new crystalline sponge that does not require activation and, most surprisingly, can capture guest molecules within one minute. [ABSTRACT FROM AUTHOR]

Renal cell carcinoma (RCC) is a malignancy with poor prognosis. WNT/β-catenin signaling dysregulation, especially β-catenin overactivation and WNT antagonist silencing, is associated with RCC carcinogenesis and progression. However, the role of WNT ligands in RCC has not yet been determined. We screened 19 WNT ligands from normal kidney and RCC cell lines and tissues and found that WNT10A was significantly increased in RCC cell lines and tissues as compared to that in normal controls. The clinical significance of increase in WNT10A was evaluated by performing an immunohistochemical association study in a 19-year follow-up cohort comprising 284 RCC and 267 benign renal disease (BRD) patients. The results of this study showed that WNT10A was dramatically upregulated in RCC tissues as compared to that in BRD tissues. This result suggests that WNT10A, nuclear β-catenin, and nuclear cyclin D1 act as independent risk factors for RCC carcinogenesis and progression, with accumulative risk effects. Molecular validation of cell line models with gain- or loss-of-function designs showed that forced WNT10A expression induced RCC cell proliferation and aggressiveness, including higher chemoresistance, cell migration, invasiveness, and cell transformation, due to the activation of β-catenin-dependent signaling. Conversely, WNT10A siRNA knockdown decreased cell proliferation and aggressiveness of RCC cells. In conclusion, we showed that WNT10A acts as an autocrine oncogene both in RCC carcinogenesis and progression by activating WNT/β-catenin signaling. [ABSTRACT FROM AUTHOR]

A novel rational-fraction dispersion model is proposed for simulation of optical properties of arbitrary linear dispersive media over a wide wavelength range. A generally applicable method is proposed for estimating the parameters of this model. It is demonstrated that the rational-fraction dispersion model can fit the relative permittivity data of a material accurately and efficiently in a wide wavelength range. The new model is implemented in the finite-difference time-domain method and is applied as a powerful and computationally efficient tool for simulating nano-particles of dispersive materials in a wide wavelength range of light. [ABSTRACT FROM PUBLISHER]

A clock recovery module suitable for both burst- and continuous-mode optical receiver utilizing fiber dispersion is experimentally demonstrated for the first time. The module utilizes the nonlinear characteristics of the received nonreturn-to-zero (NRZ) optical signals experiencing the fiber dispersion and the photo-detection to extract the clock information. Experiments demonstrated its functionality in both operation modes up to 9 Gbps. © 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 52: 1747–1750, 2010; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.25347 [ABSTRACT FROM AUTHOR]

In this paper, modulation crosstalk from 1310 nm upstream optical signals to 1490 nm downstream optical signals in an distributed feedback laser diode and monitor photodiode (DFB-LD and MPD) monolithically integrated optical transceiver has been studied numerically through the time-domain traveling wave (TDTW) model. Interaction between the 1310/1490 nm wavelengths throughout the cavity originated from both cross gain modulation and cross phase modulation are the physical source of the crosstalk in the device, which were analyzed numerically in detail in the paper. A new structure is proposed to reduce the modulation crosstalk resulted from the interaction. Simulation shows that the modulation crosstalk can be drastically reduced by applying an adjustable current on the phase tuning section inserted between the DFB-LD and MPD, which verifies our design. Polarization and temperature dependence on the modulation crosstalk are also discussed. [ABSTRACT FROM AUTHOR]

Platinum and tin supported on ZnO-modified MgAl2O4 constitutes a new and efficient catalyst for the dehydrogenation of propane. The structure of the catalyst has been studied by XRD, TEM, BET, TG, H2-TPR and H2 chemisorption and catalytic properties for propane dehydrogenation have been tested on a microreactor. It has been shown that the catalyst is superior to conventional alumina-supported PtSn systems and PtSn/MgAl2O4 in terms of lifetime stability, activity and propene selectivity. The characterization results of catalysts revealed that ZnO-modified catalysts can increase the Pt dispersion and enhance the interaction between metal and support, resulting in the increase of catalytic activity for propane dehydrogenation. [ABSTRACT FROM AUTHOR]

An experimental demonstration was presented for a clock recovery scheme suitable for low-cost short-haul optical communications. This scheme utilizes the nonlinear relaxation oscillation in a directly modulated laser, which creates clock information in modulated nonreturn-to-zero optical signals. At the receiver, an injection locked oscillator is employed to extract and restore the clock. Eye diagrams of both received data signal and recovered clock demonstrate the capability of recovering clock from the data signal with an almost closed eye at ∼9 Gbps. © 2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 1654–1657, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24436 [ABSTRACT FROM AUTHOR]

A standing-wave model based on "cold" cavity mode expansion is proposed and presented for simulation of distributed feedback (DFB) semiconductor lasers. The model is validated against the well-established traveling-wave model in terms of the static and dynamic characteristics of typical DFB lasers. Effects such as the longitudinal variation of carrier and photon densities and nonlinear gain saturation, known as the spatial and spectral hole burning, respectively, are all included in this model. Simulation examples show that the proposed approach is computationally more efficient than the traveling-wave model. The impact of the expansion mode truncation on the accuracy and efficiency is also investigated and discussed. [ABSTRACT FROM AUTHOR]

Bragg grating, structures based on dielectric slot waveguide, are investigated theoretically for potential applications as optical resonators and filters. Important device performance parameters, such as the reflection spectrum, the peak reflectivity, and the field confinement factor, are examined as functions of key waveguide and grating design parameters. [ABSTRACT FROM AUTHOR]

An improved full-vector finite-difference (FD) complex mode solver for circularly symmetric optical waveguides is developed and validated. The formulations are derived from Taylor expansion of transverse electric and magnetic fields and match of boundary conditions at radial index discontinuities. Calculation of the guided and leaky modes of step index fibers, Bragg fibers, and surface plasmon polaritons structures shows significant improvement in terms of accuracy and rate of convergence without increase of computational efforts, in comparison with the conventional FD scheme based on the average-index approximation. It is demonstrated that the performance of the new scheme is robust for high-order modes and waveguides with high index contrast. Contrary to the conventional FD solvers that claim the magnetic field formulation is more rigorous than the electric field formulation, the improved solver yields practically identical results for both formulations. [ABSTRACT FROM PUBLISHER]

A novel clock recovery scheme utilizing the relaxation oscillation in a directly modulated laser (DML) for burst-mode transmission is proposed for the first time. In this scheme, the DML generates the clock tone along with the transmitted non-return-to-zero data in the optical signal. An injection-locked oscillator (ILO) is employed in the receiver to extract the clock tone and restore the clock. The proposed scheme is investigated systematically and verified by simulations with different laser modulation currents as well as some nonideal characteristics of the system. The simulation results show that the low cost clock recovery method using an ILO in an optical link using a regular DML is highly efficient for burst-mode transmission at 10 Gbps. [ABSTRACT FROM PUBLISHER]

Waveguide Bragg grating structures with strong index corrugations are analyzed by the complex mode-matching method. As the index corrugation increases, the peak wavelength of the reflection spectrum is shifted towards shorter wavelength from the conventional Bragg condition due to the energy storage effect. It is shown that the peak wavelength corresponds to the center of the stop-band of the Floquet-Bloch mode. An efficient and reliable iterative method is proposed for design of grating structures with strong corrugations. [ABSTRACT FROM PUBLISHER]

F-doped TiO2 nanotubes were prepared by impregnation method. The prepared catalysts were characterized by XRD, TEM, and XPS. The photocatalytic activity of F-doped TiO2 nanotubes was evaluated through the photodegradation of aqueous methyl orange. The experiments demonstrated that the F-doped TiO2 nanotubes calcined at 300 °C possessed the best photocatalytic activity. Compared with pure TiO2 nanotubes, the doping with F− significantly enhanced the photocatalytic efficiency. The high photocatalytic activity was ascribed to several beneficial effects produced by F-doping: creation of oxygen vacancies, presence of Ti3+, and so on. [ABSTRACT FROM AUTHOR]

Accurate rational approximations to the square root operators are crucial for the bidirectional beam propagation method in simulation of strongly reflective structures. An assessment and comparison of various commonly used rational approximations is performed for both transverse electric (TE) and transverse magnetic (TM) waves. The range of validity and level of accuracy for the different approximations are studied by investigating the structures with varying reflection intensities. Guidelines for accurately modeling of evanescent and propagating modes are provided. [ABSTRACT FROM PUBLISHER]

Abstract  Two new blue luminescent Zn(II) complexes, [ZnL2(H2O)]Cl2 · H2O (1) and [ZnL2Cl][ZnLCl2] · NO3 (2) (L = 2-aminomethylbenzimidazole) have been synthesized and characterized spectroscopically and crystallographically. The structure of complex (1) can be described as a square pyramid. In the complex (2), there are two units [ZnLCl2] (a), and [ZnL2Cl] (b), which have a distorted tetrahedral geometry and a slightly distorted trigonal bipyramidal coordination geometry, respectively. In these complexes, significant multiple inter- and intra-molecular hydrogen bonding and π–π stacking interactions are shown. These contacts lead to aggregation and supramolecular assembly of complexes (1) and (2) into 3D and 2D frameworks, respectively. Fluorescent analysis in the dilute DMF solution and solid state shows that both complexes exhibit intense emission in blue region. They display high blue luminescence quantum efficiency due to a metal-to-ligand charge transfer (MLCT) and have a bathochromic shift of the emission energy compared with the free ligand L. The emission intensity of complex (2) is higher than that of complex (1). [ABSTRACT FROM AUTHOR]

A fourth-order finite-difference formula is applied to bidirectional beam-propagation method based on scattering operators. The method is shown to provide significant improvement in accuracy and efficiency, particularly for waveguide structures of high index contrast. [ABSTRACT FROM PUBLISHER]

A high-order split-step algorithm is developed and presented to solve the time-dependent coupled-wave equations for traveling-wave optical fields in a variety of grating-based optical devices such as the distributed feedback and distributed Bragg reflector lasers. Based on the Suzuki's fractal decomposition approach, Lie-Trotter-Suzuki product formula is used to construct the higher order solution that converges faster than the conventional split-step method. The accuracy and efficiency of the new scheme are assessed by way of examples and shown to be superior to those of the conventional method. [ABSTRACT FROM AUTHOR]

A highly accurate reflective scheme is developed for analysis of two-dimensional (2-D) waveguide discontinuities by using the fourth-order finite-difference (FD) formula. It is demonstrated that the new method achieves a significantly higher accuracy/computation cost ratio in comparison with the conventional FD method. Furthermore, the advantage of the new method is more pronounced for the case of high-index-contrast structures with small feature sizes [ABSTRACT FROM PUBLISHER]

A comprehensive review of the optical transceivers for fiber-to-the-premises applications is presented, with emphasis on system requirements and enabling technologies. Recent progress in photonic integration to realize low-cost, high-performance, and compact optical transceivers for the optical network terminal is reviewed [ABSTRACT FROM PUBLISHER]

Au/CeO2 catalysts prepared by co-precipitation (CP) and deposition-precipitation (DP) methods were tested for low temperature CO oxidation reaction. The structural characters and redox features of the catalysts were investigated by XRD, XPS and H2-TPR. Their catalytic performances for low temperature CO oxidation were studied by means of a microreactor -GC system. It showed that the catalytic activities of Au/CeO2 catalysts greatly depended on the preparation method. The catalysts prepared by DP method exhibited a surprisingly higher activity towards CO oxidation than that prepared by CP method. This may arise from the differences in the particle sizes of Au and redox properties of the catalysts. The low Au loading and the resistance to high temperature of DP-prepared catalyst made it more applicable. [ABSTRACT FROM AUTHOR]

CuO/Ce0.8Zr0.2O2 and CuO/CeO2 catalysts were prepared via a impregnation method characterized by using FT-Raman, XRD, XPS and H2-TPR technologies. The catalytic activity of the samples for low-temperature CO oxidation was investigated by means of a microreactor-GC system. The influence of the calcination temperature and different supports on the catalytic activity was studied. [ABSTRACT FROM AUTHOR]

A finite-difference-based mode-matching method (FD-MMM) is developed and demonstrated for three-dimensional (3-D) optical waveguide structures with arbitrary index profiles and multiple scattering interfaces along the waveguide axis. The computation domain is enclosed by a perfectly conducting box coated by a perfectly matched layer (PML). Semivectorial approximation is employed to simplify the formulations and calculations. Tradeoff and guidelines for choice of the PML parameters in the mode-matching analysis are discussed by comparison with known benchmark solutions for a two-dimensional (2-D) structure. The method is subsequently applied to and validated for 3-D structures in which both single and multiple scattering interfaces are simulated. [ABSTRACT FROM PUBLISHER]

This paper presents a novel split-step time-domain beam-propagation method (TD-BPM) for simulation of time-domain pulse propagating in optical waveguide devices. Different from the traditional methods, where the time-marching step is strictly limited by the relation Δt=Δz/vg, the new split-step algorithm allows much more relaxed temporal and spatial steps, and therefore is much more efficient. [ABSTRACT FROM PUBLISHER]

A systematic investigation of gain-clamped semiconductor optical amplifiers (GC-SOAs) based on the second-order index-coupled DFB gratings is carried out by way of simulation. In particular, we focus on the main effects of the radiation loss caused by the first-order diffraction of the gratings on the amplifier performance. The magnitude of the total complex coupling coefficient is the main factor to determine the level of gain clamping. We demonstrate that a high-performance GC-SOA can be realized by using purely loss-coupled second-order DFB gratings with more relaxed tolerance on grating strength and period. It is shown that, in the presence of weak reflection-related coupling, the parasitic radiation loss associated with the second-order grating always helps to expand the linear amplification region and to reduce the longitudinal spatial hole burning along the cavity. Further, we demonstrate through comparison that the GC-SOAs have higher saturation power and much shorter carrier lifetime than the conventional SOAs. An improved design by longitudinal variation of the grating duty cycle is proposed such that the noise performance of the amplifier can be enhanced without much sacrifice on the linear amplification regime. [ABSTRACT FROM AUTHOR]

This paper presents a new simulation method for modeling and simulation of high-density integrated optical circuits based on high index contrast (HIC) waveguides with complex topology. The method combines the time-domain reflective beam propagation method (TD-RBPM) and the slow-wave finite-difference time-domain method and is hence referred to as the time-domain hybrid BPM (TD-HBPM). It is capable of handling arbitrary optical integrated circuits with perpendicularly located input and output ports. The application to the two HIC optical circuits shows the accuracy and efficiency of this method. [ABSTRACT FROM PUBLISHER]

A detailed theoretical investigation of an integration of a semiconductor optical amplifier (SOA) and distributed Bragg reflector (DBR) laser is presented. The dependence of the device performance on those key design parameters such as the lasing wavelength, light injection direction (co- and contra-propagation), lasing power of the DBR laser, and the biasing condition of the SOA is examined systematically by means of a comprehensive time-do- main traveling-wave model. As this integrated structure is particularly designed for high saturation power and fast gain dynamics, these characteristics are simulated and compared with the results from the conventional structures. Depending on different requirements, superior performance on either saturation power or noise figure without compromise on the optical gain can be achieved by different integration configurations (i.e., by different light injection directions). For the structure with the light injection from the output end of the SOA (namely, the integrated SOA-laser structure), the fast gain dynamics is found through simulation, which helps to reduce the large-signal waveform distortion In the amplification of narrow pulses. [ABSTRACT FROM AUTHOR]

TiO2 supported nano-Au catalysts were prepared by solvated metal atom impregnation (SMAI) method. The catalysts were characterized by means of AAS, TPD, H2 reduction desorption (H2-RD), XRD, TEM, XPS and tested for low-temperature CO oxidation. XRD and TEM results showed that the pretreatment temperature had an influence on the particle size of Au/TiO2 catalysts. The average particle size increased with the increase in pretreatment temperature. XPS indicated that gold in the catalysts was presented in the form of metallic state clusters. Catalytic studies showed these catalysts were very active and stable in low-temperature CO oxidation. The CO oxidation activity of the catalysts increased as the Au particle size decreased. The measurement results of AAS, TPD and H2-RD revealed that there were some organic fragments on the surface of Au particles which might be responsible for the high stability of the Au/TiO2 catalysts. [ABSTRACT FROM AUTHOR]

TiO2 supported nano-Au catalysts were prepared by solvated metal atom impregnation (SMAI) method. The catalysts were characterized by means of AAS, TPD, H2 reduction desorption (H2-RD), XRD, TEM, XPS and tested for low-temperature CO oxidation. XRD and TEM results showed that the pretreatment temperature had an influence on the particle size of Au/ TiO2 catalysts. The average particle size increased with the increase in pretreatment temperature. XPS indicated that gold in the catalysts was presented in the form of metallic state clusters. Catalytic studies showed these catalysts were very active and stable in low-temperature CO oxidation. The CO oxidation activity of the catalysts increased as the Au particle size decreased. The measurement results of AAS, TPD and H2-RD revealed that there were some organic fragments on the surface of Au particles which might be responsible for the high stability of the Au/TiO2 catalysts. [ABSTRACT FROM AUTHOR]

A lime-domain reflective beam propagation method (TD-RBPM) is presented for the analysis of optical pulse propagation and reflection in waveguide structures with multiple discontinuities. By utilizing an implicit scheme, the method allows relatively large time steps and, therefore, is highly efficient. The accuracy of the method is verified by simulating a time-domain Gaussian pulse reflected and transmitted from a multiple period grating and a four-layer antireflection coating structure. [ABSTRACT FROM AUTHOR]

We present a simple noniterative scheme for calculation of reflectivity for optical waveguide facet. By multiplying an operator to the standard reflection formula, we reduce the original matrix inversion involving the implicit square-root operators to an explicit solution. The new formula is extremely simple and easy to implement, especially for the TE case, where an analytical expression is obtained without involving any matrix inversion. The accuracy and efficiency of the new solution scheme are assessed and verified by numerical experiments. [ABSTRACT FROM PUBLISHER]

A field-based numerical method for simulation of field scattering at discontinuities along three-dimensional optical waveguides of arbitrary index profiles is presented. Different from the previous work based on directly diagonalizing the characteristic matrices, we developed a robust and efficient iterative scheme by using an improved Neumann series. Superb performance of the scheme in terms of accuracy and efficiency is demonstrated and verified. [ABSTRACT FROM AUTHOR]

Performance of the gain-clamped semiconductor optical amplifier (GC-SOA) based on the distributed Bragg reflector (DBR) structures is investigated by a comprehensive broad-band time-domain traveling wave model Critical factors, e.g., the material gain profile, the waveguide grating structures, the longitudinal variation of the optical field, and the carrier density as well as the broad-band spontaneous noise emission are considered in the model. The effects of operation parameters (e.g., the electrical bias current and the input optical power) and design parameters (e.g., the normalized coupling coefficient κL and the lasing wave-length position λ[SUBL]) on device performance are examined in detail. Based on the results of the performance simulation, guidelines for design optimization are discussed and, in particular, unbalanced grating configurations combined with nonuniform current injection schemes are proposed to reduce the noise figure without much sacrifice on other device performance. [ABSTRACT FROM AUTHOR]

A robust computational scheme for calculation of multiple modes of optical waveguides is developed and presented. The new method uses the beam propagation methods to generate the modal fields and a digital signal processing technique for mode parameter extraction. It can be applied to both guided and leaky modes with different formulations (i.e., scalar, semi-vector or full-vector) and discretizations (e.g., finite difference or finite element). Salient features of the new method are discussed and advantages over other computational methods based on boundary-value eigen solvers and initial-value propagation solvers are demonstrated by way of examples. [ABSTRACT FROM AUTHOR]

Radiation patterns of scattered fields with arbitrary azimuthal orders in multilayer planar waveguides and laser cavities with circularly symmetric gratings are formulated based on the volume current method. Full-wave Green's function analysis based on the integral transform method lies at the heart of this approach. Unlike the conventional approach, the dyadic Green's function relates some auxiliary fields to some auxiliary sources in the spectral domain. These auxiliary functions are defined to facilitate the spectral domain formulation in the cylindrical coordinate system and the use of transfer matrix method for obtaining a closed-form solution of the spectral Green's function in multilayer planar structures. More importantly, it is shown that the far-field pattern of the scattered field can be expressed directly in terms of the auxiliary fields in the Hankel transform domain. [ABSTRACT FROM AUTHOR]

We present a preconditioner based on the paraxial approximation for the square-root operator to realize a stable and efficient iterative scheme in the reflective beam propagation method. The new preconditioner is shown to be highly effective in facilitating robust, efficient, and accurate solutions for computation of reflected and transmitted fields due to index discontinuities along optical waveguides, due primarily to the improvement on the condition number of the operator used. [ABSTRACT FROM PUBLISHER]

A general procedure for design of photonic crystal fibers (PCFs) with desirable dispersion properties is presented. The design model is based on the combination of a rigorous vector mode solver and a scaling transformation for the dispersion properties of the PCFs. In comparison with the conventional design method, the new design procedure is more efficient and can be readily automated for the purpose of design optimization. Several applications of the design procedure, e.g., the design optimization for dispersion shifted fibers, dispersion flattened fibers, and dispersion compensation fibers, are demonstrated and discussed. [ABSTRACT FROM PUBLISHER]

The generalized space mapping (GSM) technique is employed for modeling and simulation of photonic devices. The mapping is established between the parameter spaces of coarse and fine models so that accuracy of the coarse model is significantly improved for a given range of parameters. To demonstrate the usefulness of this technique, modeling and simulation of an optical waveguide facet is used as an application example. Two methods are adopted for the coarse model, i.e., the transfer matrix method (TMM) and the free space radiation mode (FSRM) method. The time-intensive and accurate finite-difference time-domain (FDTD) method is used as the fine model for model calibration. The mapping-enhanced coarse models show significant improvement in terms of accuracy. Further, a criterion is established to measure the accuracy of the coarse models. It is shown that the FSRM is one order of magnitude more accurate than the TMM for the TE case, however, the two methods have almost the same level of accuracy for the TM case. [ABSTRACT FROM PUBLISHER]

A new scheme for the scalar finite-difference timedomain (FDTD) method with perfectly matched layer boundary conditions in cylindrical coordinate system is developed and presented. The FDTD method is applied successfully for the calculation of both guided and leaky modes of optical waveguides with circular symmetry. [ABSTRACT FROM AUTHOR]

A three-dimensional algorithm with the perfectly matched layer (PML) absorbing boundary condition (ABC) for the scalar wave equation in the time domain is presented for general inhomogeneous lossy or loss-free problems. The proposed PML ABC is applicable to practical finite difference schemes treating the time-domain wave equation, such as the time-domain wave-potential (TDWP) technique and the time-domain scalar wave equation approaches to the analysis of optical structures. The time-domain wave equation for lossy media is expressed in terms of stretched coordinate variables. The algorithm is tested for homogeneous and inhomogeneous media. We demonstrate applications to open (radiation) problems and to port terminations in high-frequency circuit problems. New PML conductivity profiles are developed for use with the second order wave equation, which offer lower reflections in a wider frequency band in comparison with the commonly used (in finite-difference time-domain (FDTD) algorithms) profiles. The effect of the termination walls on the overall PML performance is studied and the best choices are singled out. [ABSTRACT FROM AUTHOR]

Space-mapping (SM) technique is applied for design optimization of antireflection (AR) coatings for photonic devices such as the semiconductor optical amplifiers (SOA). The approximate and efficient transfer matrix method (TMM) serves as the coarse model for design optimization, whereas the time-intensive and accurate finite-difference time-domain (FDTD) method is used as the fine model for model calibration. A mapping is established between the parameter spaces of the coarse and the fine models so that the fine model design becomes the inverse mapping of the optimized coarse model design. Remarkable performance of the SM technique in terms of efficiency and accuracy in the design optimization is demonstrated by way of examples. It is shown that, in the context of multilayer coating design, the desired broadband ultralow reflectivities can be obtained within three fine model (FDTD) calculations. [ABSTRACT FROM PUBLISHER]