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Additive manufacturing (AM) is a fast-growing technology that supports the rapid fabrication of prototypes. Already, employing AM technologies in early product development stages can help to accelerate the time from conceptualisation phase to the market entry. Furthermore, advances in the field of materials, such as highly transparent resins in the visible wavelength spectrum, also open application potentials for the design and fabrication of optical components. Three highly transparent resins from different suppliers are studied in this work regarding their influence on the geometrical and optical properties of additively manufactured components. The different materials were processed using a masked stereolithography 3D printer. Geometrical and optical properties of the generated test samples were analysed by means of laser scanning microscopy and spectrophotometry, respectively. A clear correlation between optical properties of the resin and the solidified samples was identified. It was further found that while spin coating does not significantly affect the geometrical properties, a strong influence on the resulting optical properties could be observed. The highest transmission properties, in the range of up to 90%, were determined for samples that were spin-coated on both surfaces. Thus, applying a spin coating operation to additively manufactured optical components is recommended for the highest transmission properties. [ABSTRACT FROM AUTHOR]

In this contribution, we address quantum transport in long periodic arrays whose basic cells, localized potentials U (x) , display certain particular features. We investigate under which conditions these "local" special characteristics can influence the tunneling behavior through the full structure. As the building blocks, we consider two types of U (x) s: combinations of either Pöschl–Teller, U 0 / cosh 2 [ α x ] , potentials (for which the reflection and transmission coefficients are known analytically) or Gaussian-shaped potentials. For the latter, we employ an improved potential slicing procedure using basic barriers, like rectangular, triangular and trapezoidal, to approximate U (x) and thus obtain its scattering amplitudes. By means of a recently derived method, we discuss scattering along lattices composed of a number, N, of these U (x) s. We find that near-resonance energies of an isolated U (x) do impact the corresponding energy bands in the limit of very large Ns, but only when the cell is spatially asymmetric. Then, there is a very narrow opening (defect or rip) in the system conduction quasi-band, corresponding to the energy of the U (x) quasi-state. Also, for specific U 0 's of a single Pöschl–Teller well, one has 100% transmission for any incident E > 0 . For the U (x) parameters rather close to such a condition, the associated array leads to a kind of "reflection comb" for large Ns; | T N (k) | 2 is not close to one only at very specific values of k, when | T N | 2 ≈ 0 . Finally, the examples here—illustrating how the anomalous transport comportment in finite but long lattices can be inherited from certain singular aspects of the U (x) s—are briefly discussed in the context of known effects in the literature, notably for lattices with asymmetric cells. [ABSTRACT FROM AUTHOR]

The object of the presented paper is to demonstrate the possibility of equalizing the transmission properties of networks described by graphs with an equal number of nodes of the same degree but differing in diameter and average path length. A node of a graph is understood to be a specialised device performing commutation and transmission functions, while an edge is understood to be a transmission link. It was assumed that this alignment can be achieved by controlling the transmission resources assigned to specific edges of a graph through which the network nodes communicate with each other. The concept of transmission resource, counted in contractual units, is understood as, for example, the number of time slots or the bandwidth of the links used to transmit information. The authors show that with the proposed method, the equalization of the mentioned network properties is achieved with a minimal increase in the global resources used for transmission. [ABSTRACT FROM AUTHOR]

In the present work, the optical transmission properties of a symmetric ternary periodic structure, made of superconductor and dielectric materials, are studied by using the transfer matrix method. To design a one-dimensional symmetric ternary photonic crystal, we have considered a superconductor of Bismuth strontium calcium copper oxide (BSSCO) along with silica (SiO2) and silicon (Si) as dielectric materials that are in shapes of nanolayered films. We investigate the effects of the operating temperature, number of layers, and angle of incidence on the width of the enlarged photonic bandgap obtained in the visible range, and also on the peak position of the defect mode lying in the gap, which is attributed to the symmetry in the periodic structure. It is noted that that the defect mode peak position with transmission ≈ 100% shows red-shift, and the forbidden gap slightly increases with increase in the superconductor temperature. Furthermore, the defect mode shows minor red-shift with increase in the number of unit cells, where there is a decrease in the enlarged photonic bandgap width. With an increase in the incident angle, the enlarged bandgap width decreases, and the defect mode peak position exhibits blue-shifts in both cases of transverse eclectic (TE) and transverse magnetic (TM) modes. Such kind of tunablity is more dominant for TM wave as compared to TE wave. Therefore, the present analysis based on the bandgap and defect mode tunability can be exploited in designing temperature-sensitive mirrors, monochromators optical filters, and tunable visible range devices like solar cells. [ABSTRACT FROM AUTHOR]

Recently, the vibration induced by viaduct rail transit has become a severe problem during train operation. To investigate the transmission properties of the vibration energy of the viaduct track, the procedures of transmission and dissipation of the vibration energy are analyzed based on the power flow theory of single-stage and multi-stage vibration isolation system. A viaduct track finite element (FE) model is developed, and the accuracy of the model is verified by observational acceleration. Combined with the FE model and power flow theory, the transmission and distribution characteristics of energy in the viaduct tracks are analyzed. The results show that the peak value of the vibration power is reached at the natural frequency of the track structure; the vibration energy decreases from top to bottom of the track structure in the frequency range of 1 ~ 1 000 Hz; the fastener system significantly consumes high-frequency (100 ~ 1 000 Hz) vibration energy and low-frequency (1 ~ 100 Hz) vibration energy is significantly consumed by the support of the track slab; the power flow index can indicate the transmission, distribution, and dissipation properties of the energy; and optimal vibration reduction effect can be obtained by designing the stiffness and damping of the fastener system and the support of the track slab. [ABSTRACT FROM AUTHOR]

A hybrid plasmonic waveguide structure composed of graphene-coated nanotube with a dielectric substrate is proposed in this paper. Transmission properties of the fundamental mode are studied by the finite element method (FEM). The results reveal that the mode transmission properties are greatly dependent on the nanotube radius and internal–external diameter ratio, gap distance, nanotube permittivity, as well as chemical potential of graphene. Meanwhile, it is compared with the graphene-coated nanowires with a dielectric substrate (Hajati and Hajati in Plasmonics, 2018. https://doi.org/10.1007/s11468-017-0524-2). By optimizing the parameters, the structure could achieve long-range propagation with the propagation length about 12.56 um. Moreover, it could realize deep-subwavelength confinement with the normalized mode area only ~ 10–7 in the mid-infrared (mid-IR). This structure may offer a certain theoretical basis for integrated nanophotonic devices to achieve long-distance transmission in the deep-subwavelength range. [ABSTRACT FROM AUTHOR]

A one-dimensional phononic crystal model based on Galois structure is proposed. The transmission coefficients of the elastic waves are numerically calculated and compared with those of the periodical structure. Band gaps are found and the results show that if the number of medium layers is small, the frequency range of the band gap in the Galois structure and periodic structure is basically the same. However, with the increase of the number of medium layers, the frequency range of the band gap in the Galois structure increases, and the localized resonant modes appear in the band gap. The study of transmission properties of Galois structures is helpful to understand the propagation properties of classical elastic waves in aperiodic composite structures. [ABSTRACT FROM AUTHOR]

Current classifications of sporadic Creutzfeldt–Jakob disease (sCJD) identify five subtypes associated with different disease phenotypes. Most of these histopathological phenotypes (histotypes) co-distribute with distinct pairings of methionine (M)/valine (V) genotypes at codon 129 of the prion protein (PrP) gene and the type (1 or 2) of the disease-associated PrP (PrPD). Types 1 and 2 are defined by the molecular mass (~ 21 kDa and ~ 19 kDa, respectively) of the unglycosylated isoform of the proteinase K-resistant PrPD (resPrPD). We recently reported that the sCJDVV1 subtype (129VV homozygosity paired with PrPD type 1, T1) shows an electrophoretic profile where the resPrPD unglycosylated isoform is characterized by either one of two single bands of ~ 20 kDa (T120) and ~ 21 kDa (T121), or a doublet of ~ 21–20 kDa (T121−20). We also showed that T120 and T121 in sCJDVV have different conformational features but are associated with indistinguishable histotypes. The presence of three distinct molecular profiles of T1 is unique and raises the issue as to whether T120 and T121 represent distinct prion strains. To answer this question, brain homogenates from sCJDVV cases harboring each of the three resPrPD profiles, were inoculated to transgenic (Tg) mice expressing the human PrP-129M or PrP-129V genotypes. We found that T120 and T121 were faithfully replicated in Tg129V mice. Electrophoretic profile and incubation period of mice challenged with T121−20 resembled those of mice inoculated with T121 and T120, respectively. As in sCJDVV1, Tg129V mice challenged with T121 and T120 generated virtually undistinguishable histotypes. In Tg129M mice, T121 was not replicated while T120 and T121−20 generated a ~ 21–20 kDa doublet after lengthier incubation periods. On second passage, Tg129M mice incubation periods and regional PrP accumulation significantly differed in T120 and T121−20 challenged mice. Combined, these data indicate that T121 and T120 resPrPD represent distinct human prion strains associated with partially overlapping histotypes. [ABSTRACT FROM AUTHOR]

The aim of this paper is to present an analytical method to quantitatively address the influence of a focusing illumination on the optical response properties of a metasurface illuminated by a finite-size beam. Most theoretical and numerical studies are performed by considering an infinite periodic structure illuminated by a plane wave. In practice, one deals with a finite-size illumination and structure. The combination of the angular spectrum expansion with a monomodal modal method is used to determine the beam size needed to acquire efficient properties of a metasurface that behaves as an anisotropic plate. Interesting results show that the beam-size can be as small as 5 × 5 periods to recover the results of a plane wave. Other results also show that the beam-size can be used as an extrinsic parameter to enhance the anisotropic metasurface performance and to adjust its expected properties finely (birefringence and/or transmission coefficient). These findings are important for the design of real (finite) structures and can be adapted for experimental conditions to achieve optimized results and take full advantage of the metamaterial properties. [ABSTRACT FROM AUTHOR]

A metal-insulator-metal (MIM) waveguide with double overlapping annular rings is proposed, and its transmission properties are simulated and characterized by the finite element method. The results show that the transmission valley appears in the transmission spectra when the straight MIM waveguide output port has a positional angular deviation θ relative to the incident port. Compared with the symmetric structure ( θ = 0°), the filtering properties of the asymmetric structures ( θ > 0°) are greatly improved. And compared to the MIM waveguide with single ring resonator, the filter characteristic of MIM waveguide with the double overlapping rings is superior to that of single ring resonator. For the asymmetric structure, due to the fact that parts of coupled MIM waveguide output port locates at the magnetic nodes of the standing waves in the ring resonator, there is a transmission minimum. Moreover, the asymmetric MIM waveguide can easily detect the refractive index changes of the filled media inside of resonator cavities, its potential applications in sensors. [ABSTRACT FROM AUTHOR]

We investigate the plasmon-induced transparency (PIT) effect in dual-stub-coupled metal-insulator-metal waveguide. The transmission line theory is employed to analyze the relationship between the transmission properties and geometrical parameters. It is found that by incorporating tunable refractive index materials with the proposed structure, a tunable PIT and slow light effect can be obtained in a constant stub separation design. The theoretical results show that a shift of 70 THz in the central wavelengths of transparency window can be obtained when the refractive index of the dielectric varies. In addition, the group index can be tuned from 24 to 36, which provides an effective method to adjust the slow light properties in the proposed waveguide. This letter opens up the possibility for the realization of tunable slow light devices in highly integrated optical circuits. [ABSTRACT FROM PUBLISHER]

Extraordinary optical transmission (EOT) is widely accepted as a resonant phenomenon. However, the nonresonant EOT phenomenon of subwavelength metallic nanohole arrays on a metallic thin film is significant for harvesting of broadband light, confining optical power in small area, and enhancing local electric field. To achieve nonresonant EOT, a novel paradigm structure comprising periodic diamond-shaped nanohole arrays engraved on a thin gold film is proposed. The transmission properties of the diamond-shaped nanohole arrays are calculated using the finite-element method. Results show that this paradigm structure facilitates a broadband and enhanced transmission in the infrared region. In addition, the effects of incident polarization and structural parameters on the transmission property are also studied. [ABSTRACT FROM PUBLISHER]

In order to achieve a double-frequency filter, we design a sandwiched structure with a dual-prism total reflection configuration. The sandwiched structure consists of one metal layer and two same media layers. The transmission properties are studied through the standard transfer matrix method. Such system can form two hybrid cavity-surface plasmon-polariton modes. The coupling of the two hybrid modes results in resonance tunneling effect and mode splitting. Mode splitting leads to the coupled double peaks. The difference of double-peak frequencies can be adjusted through changing the metal thickness, and the position of double peaks can be also tunable through changing incidence direction. Such system can be used in designing double-frequency filters and terahertz emission devices. [ABSTRACT FROM PUBLISHER]

We present the first demonstration of combined wavelength-division multiplexed (WDM) and mode-division multiplexed (MDM) optical transmission in a hollow-core photonic bandgap fiber (HC-PBGF). For this purpose a novel low loss, broadband 310 m long HC-PBGF with a 37 cell (37c) core geometry is used. The modal properties of the HC-PBGF are characterized in detail, showing an absence of surface modes and low modal crosstalk, which enable WDM and MDM transmission with record high capacity (73.7 Tb/s) for a HC-PBGF. Several modulation formats have been tested, showing very good and stable performance. The transmission properties are assessed by looking into both single-mode transmission and MDM transmission, showing good agreement with the modal characterization of the 37c HC-PGBF. [ABSTRACT FROM PUBLISHER]

We theoretically demonstrate that at certain frequencies two-dimensional dielectric photonic crystals (PCs) may be regarded as either epsilon-near-zero or mu-near-zero materials. We show that the transmission through a slab of such materials upon normal incidence is normally non-unity and decays with slab thickness. However, when the incident angle increases slightly, the transmittance experiences a dramatic increase due to the Brewster effect. The combination of the tunneling and resonance effects makes such materials good candidates for almost perfect bending waveguides and cloaking in waveguides. The zero index also enables applications of focusing and directive emission. At last, the distinction between the single-zero and double-zero media is discussed. In all of the above results, the numerical simulations perfectly match with theoretical predictions from the effective medium analysis. [ABSTRACT FROM AUTHOR]

Contact resistance has always been an issue for semiconducting carbon nanotubes (CNT). This paper presents a comparative study on open-ended semiconducting carbon nanotube (4, 0) two-probe systems with metal electrodes of platinum, copper and gold. The local density of states and transmission coefficients has been calculated to explain the electronic structure and transmission properties of two-probe systems. Contact resistance for each two-probe system has been derived from their current-voltage characteristics. Calculations are based on first-principle quantum mechanical density functional, matrix Green's function methods and Landauer-Buttiker formula. Contact resistance is calculated to be highest for the Au electrode while it is least for the Pt electrode. [ABSTRACT FROM AUTHOR]

Twisted nematic type THz polarization control devices using liquid crystal immersed membrane films were fabricated by using simple stacking process. First of all, we verify the liquid crystal alignment effect in various kinds of membrane films. From THz Time-Domain Spectroscopy measurements, apparent refractive index anisotropy was observed in liquid crystal immersed Polytetrafluoroethylene and Polyolefin membrane films. Furthermore, transmission properties of twisted nematic type THz device are in rough agreement with 4 × 4 matrix calculation data. We believe that primary characteristic of THz TN device can be obtained by optimizing the fabrication processes and measurement method. [ABSTRACT FROM AUTHOR]

We investigate the transmission properties of a subwavelength plasmonic slot waveguide. We show that the transmission can be accurately calculated using the characteristic impedance of the propagating mode. Using such a model, we show that it is possible to design devices without extensive 3-D finite-difference time-domain (FDTD) computer simulations. We illustrate the approach with calculations of an asymmetric Fabry-Perot germanium photodetector based on the slot waveguide geometry, showing predicted detector efficiencies as high as 69% despite metallic losses. [ABSTRACT FROM PUBLISHER]

Based on the empirical data obtained from two typical 10-kV power networks, the transmission properties of the 10-kV power line channel are investigated using the transmission line model. The frequency range is over 40 kHz-1.5 MHz. Our results show: 1) the power attenuation through the channel is about 20-25 dB/km when the channel does not have a branch and 2) the channel is time dispersed. In the frequency domain, the amplitude response is frequency selective while the phase response is linear. In the time domain, the impulse response shows a delay spread. The rms delay spread and the coherence bandwidth are in correlation with the network structure, and the corresponding values are on the order of 10 µs and 10 kHz. 3) The narrow fading of the channel follows Nakagami-m distribution. The channel is varying weakly with respect to time. When the data rate is up to kbps, the channel can be regarded as time invariant. [ABSTRACT FROM AUTHOR]

Transmission properties of the power-line channels play a very important role in the reliability of signal propagations. This paper discusses the physical signal transmission property on the broadband power-line channels based on transmission-line theory, mode propagation theory and electromagnetic-field radiation theory. It also examines the carrier signal propagating through the multi-path line channel by empirical data. The correlations among the channel attenuation and frequency, length of the path, loads and branches are analyzed, respectively, and the path loss is calculated based on empirical data and linear regressive analysis. In the end, the impact of the radiation from carrier signals on the channel characteristic measurement is concluded. [ABSTRACT FROM AUTHOR]

This paper presents a theoretical study of the single-mode and birefriengence condition of the silicon photonic wires using the imaginary distance beam propagation method. The photonic wires are suitable for integration with active one-dimensional silicon photonic bandgap waveguides. This inherently will reduce the propagation loss caused by the scattering factors within the photonic bandgap structure itself. To the best of our knowledge, we provide for the first time, a systematic study of the various physical parameters that can affect the Q-factor and transmission properties in such waveguides. In order to make this technology viable, the waveguides must be tunable, have low attenuation, possess high Q-factor, and can be switched. Can these be achieved simultaneously without changing the device width and height dimensions? Furthermore, can we meet these aims without placing unrealistic demands in fabrication? The electrical switching of this device is implemented using a p-i-n optical diode. The diode is predicted to require an on state power of 81 nW with rise and fall times of 0.2 and 0.043 ns, respectively. The length of the microcavity and the diameter of the air holes are finely tuned with reference to the Q-factor and transmission. It will be shown that for certain desired resonant wavelength, the Q-factor and transmission properties can be optimized by tuning the length of the cavity and the diameter of the two inner most air holes. This method allows ease of fabrication by not having to vary the waveguide width and height to obtain the tuning effects. Optical simulation was performed using the three-dimensional finite-difference time-domain simulation method [ABSTRACT FROM PUBLISHER]

In this study, the transmission properties of photonic crystals with multiple periodic defects are studied by using a full-wave approach. The high convergence rate of the employed technique has allowed us to accurately and efficiently predict the filtering behavior of the considered structures. Results are presented for both TE and TM polarizations, showing the transmission efficiencies as a function of the involved parameters. In order to give more physical insight, a comparison with a simpler one-dimensional model has been provided. From our numerical investigation, it turns out that, by suitably configuring the photonic bandgap, it is possible to shape the filtering properties in TE polarization in a simple and versatile way. [ABSTRACT FROM PUBLISHER]

The effects of terminal groups on the electron transport between metal electrodes and molecule are investigated through metal-molecule-metal systems using the first principles method, which is based on the density functional theory, with norm-conserving nonlocal pseudopotentials and nonequilibrium Green's functions. Eight Au-molecule-Au open systems are constructed and numerically examined, where gold atoms are used as electrode, benzene and borazine as core molecules, and sulphur (S), oxygen (O), selenium (Se), and cyano-group (CN) as terminal groups. Gold electrodes are described through a three-dimensional atomic model. The current-voltage (I-V) characteristics, density of states, and transmission functions of constructed systems are calculated and analyzed. Results show that the transmission properties of the systems are affected greatly by the terminal groups and are dependent on the core molecule as well. Se is demonstrated as the best terminal group to couple borazine to Au electrodes and CN is the best one to couple benzene to Au electrodes. [ABSTRACT FROM PUBLISHER]

This tutorial describes the transmission, group delay time and quadratic dispersion properties of the four basic building blocs of optical filters built using ring resonators. These building blocs are single-ring resonators in either two-port (all-pass) or four-port (add/drop filter) configuration. The effect of waveguide and coupler loss is included throughout. Explicit expressions to compute the complex amplitude of the circulating wave in the ring, the Q factor, the finesse and the insertion loss are also given. Attention is drawn to the similarities between the ring resonator the Fabry-Pe´rot resonator and the Gires-Tournois interferometer. Material properties and fabrication technology are not reviewed. [ABSTRACT FROM PUBLISHER]

In this paper, an accurate and efficient characterization of two-dimensional photonic bandgap structures with periodic defects is performed, which exploits a full-wave diffraction theory developed for one-dimensional gratings. The high convergence rate of the proposed technique is demonstrated. Results are presented for both TE and TM polarizations, showing the efficiencies as a function of wavelength, incidence angle, geometrical and physical parameters. A comparison with other theoretical results reported in the literature is shown with a good agreement. The transmission properties of photonic crystals with periodic defects are studied, investigating the effects of the variation of geometrical and physical parameters; design efficiency maps and formulas are given; moreover, the application of the analyzed structures as filters is discussed. [ABSTRACT FROM PUBLISHER]

We compare quantitatively the transmission properties of various 60° bends carved into a photonic crystal based on a two-dimensional triangular lattice of holes perforating a GaAs-based heterostructure. The bends are inserted into channel waveguides defined by three missing rows in the photonic crystal. Their design is inspired by some ideas from classical integrated optics. We show experimentally that in some cases the transmission of the bent waveguide is fairly high, up to 70%, within a bandwidth of 3%, e.g., 30 nm at 1 μm, sufficient to contemplate wavelength-division-multiplexing applications. The observed performance opens the opportunity to implement a variety of optical functions in view of future photonic crystal integrated circuits for which low-loss bends constitute an essential building block. [ABSTRACT FROM PUBLISHER]

A concept of hybrid integration between planar circuits and a nonradiative dielectric (NRD) waveguide is proposed in this paper with preliminary experiments. This approach utilizes co-layered arrangement of the two dissimilar structures, which allows the NRD-guide in direct contact with (or surface mounted on) the planar circuits. Two basic building-block schemes are presented that involve microstrip line and coplanar waveguide (CPW) with the NRD-guide. The first is to deposit the NRD-guide on the top of a relatively thin microstrip substrate, thus forming unbalanced NRD-guiding hybrid circuits, while the second is to design CPW circuits directly etched on the ground planes of the NRD-guide. The unbalanced NRD-guide is subject to a certain leakage loss, but at a negligible level, and it may even be suppressed completely in certain circumstances. Such an integration technique is found consistent with the concept of low loss interconnects at millimeter-wave frequencies. In other words, the NRD-guide can be used for viable interconnects of co-layered planar circuits with a simple “put and cover” procedure. Measured results of several co-layered hybrid transitions/baluns indicate that satisfactory transmission properties can readily be achieved. The new building blocks are expected to provide an alternative design approach to three-dimensional multilayered millimeter-wave circuits and systems [ABSTRACT FROM PUBLISHER]

Hollow glass waveguides are an attractive fiber delivery system for a broad range of infrared wavelengths, including the 3-μm Er:YAG and 10.6 μm CO2 lasers. The losses for these waveguides are as low as 0.1 dB/m at the 10.6-μm wavelength for waveguides with a 700-μm bore. The guides are suitable for delivering laser powers well in excess of 100 W. Continuous power delivery for over 250 h is possible for powers less than 35 W. When stored under normal laboratory conditions, the loss is seen to change only slightly over a period up to two years [ABSTRACT FROM PUBLISHER]

In this paper, we investigated the transmission properties of multilayer films composed of magneto-optical and dielectric materials, in relation to layer stacking structure. The basic structures are made of alternating layers of these materials having a conventional symmetric periodicity with the center of the structure. Films with these basic structures exhibit an enhanced Faraday rotation effect. The rotation increases to an angle close to 45°, which is required for an optical isolator, as the repetition number of alternating layers increases. However, the transmittance decreases in these films as the rotation increases. To clarify the possibility of improving the transmittance, we also investigated films composed of multiple stacks of the basic structures. We found that, by using the multiple stacks, the transmittance can be improved without degrading the rotation characteristics [ABSTRACT FROM PUBLISHER]

In order to investigate the transmission properties in the whole solar spectrum for individual electrochromic layers in solid state devices incorporating polyaniline (PANI), Prussian Blue (PB) and tungsten oxide (WO3), the devices were fabricated with and without holes in the electrochromic coatings in several combinations. Both PANI and WO3 were deposited electrochemically on indium–tin oxide (ITO) glass substrates, while PB was deposited on top of the PANI coatings or directly on the ITO glass plates. Solid state devices were made by gluing the glass plates together with the solid polymer electrolyte poly(2-acrylamido-2-methyl-propane-sulphonic acid) (PAMPS), and thus, with and without holes in the three electrochromic coatings in different combinations, enabling us to study the optical properties of PANI, PB and WO3 separately, that is, the ‘hole’ method. This method gives good qualitative, and to a certain degree quantitative, information, which may be of valuable help in designing electrochromic devices with specific tailor-made optical properties. [ABSTRACT FROM AUTHOR]

We experimentally investigate a pass-through scheme for all-optical noise suppression in a SOA-based interferometric structure at 10 Gb/s. An input power dynamic range of ~8 dB as well as a noise suppression capability of ~4.5 dB has been demonstrated. Furthermore, the transmission properties have been investigated showing a small pre-amplified penalty of ~0.3 dB after transmission over 31 km of standard single mode fiber [ABSTRACT FROM PUBLISHER]

A PT‐symmetric periodic structure with two‐material waveguide networks is constructed. In this study, how changing the number of cells affects the transmission properties is investigated. The results show that the PT‐unbroken (broken) region of the system is only determined by the cell structure, regardless of the number of unit cells. This means that any system has the same exceptional points (EPs), regardless of the number of cells and as long as the cell structure is consistent. In addition, it is confirmed that the coherent perfect absorbers and lasers (CPA lasers) occur in our model. The transfer matrix method is used to derive a sufficient condition for achieving the CPA laser point. A simple, effective formula for predicting the CPA laser state in an N unit cell system is derived. [ABSTRACT FROM AUTHOR]