Increase In Refractive Index Research Articles

Lithography-free tailoring of thin-film nanomorphology for enhanced real-time refractive-index sensing with tunable resonance peaks in the visible spectrum

The precise detection of target substances through refractive-index sensing is essential in various fields such as environmental monitoring, food assessment, and optical applications. This study demonstrates a real-time refractive index sensor based on a liquid-infiltrated metal-insulator-metal island (MIMi) structure in a lithography-free manner. In the MIMi structure, the top layer of the metal islands is formed through solid-state dewetting, which serves as an etching mask to form nanopillars in the insulator layer. This allows for the infiltration of external substances, resulting in different structural colors depending on the refractive index. This design results in a redshift of the resonance peak as the infiltrated refractive index increases. Furthermore, by adjusting the area fraction of the metal-island layer and etching depth of the insulator layer, the resonance-peak position can be controlled within the visible range according to the target refractive index. The advantages of our design are the use of cost-effective materials and the ability to implement scalable fabrication. Our proposed method offers a convenient method to sense the target refractive index in real time.

Influence of film thickness on structural, optical, and electrical properties of sputtered nickel oxide thin films.

Utilizing radio frequency magnetron sputtering, we successfully fabricated nickel oxide thin films with different thickness (from 80 to 270 nm), and conducted an in-depth examination of their structural, morphological, optical, and electrical properties. The crystal structure and surface roughness were determined using x-ray diffraction (XRD) and atomic force microscopy (AFM), respectively. The XRD analyses showed that the films were composed of cubic nickel oxide, exhibiting a notable orientation along the (200) direction. This crystal texture partially increased when the film thickness reached 270 nm. In addition, a direct correlation between film thickness and crystallite size was observed, with the latter increasing as the former did. AFM analysis provided insights into the surface morphology, revealing metrics like the bearing area, 3D surfaces intersections, and statistical properties of surface height. These insights underscore the relationship between film thickness and surface properties, which in turn influence the overall electrical, and prominently, optical properties of the films. Employing transmittance UV-visible spectroscopy, we characterized the optical behavior of these films, noting a proportional increase in refractive index with film thickness. Additionally, resistivity was observed to increase concomitantly with film thickness. In conclusion, the deposition process's film thickness acts as a pivotal parameter for fine-tuning the structural, morphological, and optical properties of nickel oxide thin films. This knowledge paves the way for optimizing nickel oxide-based devices across various applications. RESEARCH HIGHLIGHTS: We synthesized and characterized of p-type semiconducting NiO thin films sputtered on substrates by using RF magnetron sputtering with different thickness. Advanced crystalline structures and fractal features extracted from XRD and AFM analysis. The 2D and 3Dsurface analysis of the samples indicates a complex structure with an imperfect self-similarity that suggests a multifractal structure. We represented graphically the relative representation of higher geometric objects in the AFM image. We attributed the optical and electrical properties of the samples to the crystallite size, and the concurrent reduction in oxygen vacancies and crystalline defects within the films.

Structural evolution of Ge<sub>20</sub>Se<sub>80–</sub><sub><i>x</i></sub>Te<sub><i>x</i></sub> glass networks and assessment of glass properties by theoretical bandgap

Infrared imaging systems are being updated towards greater performance as well as lighter and smaller devices. Developing infrared materials with special properties is a critical for enhancing the performance of optical systems as well as miniaturizing devices. Chalcogenide glass becomes a popular option for advanced IR materials due to its component-property tunability. Se—based glasses such as Ge<sub>33</sub>As<sub>12</sub>Se<sub>55</sub>, Ge<sub>10</sub>As<sub>40</sub>Se<sub>50</sub>, and As<sub>40</sub>Se<sub>60</sub>, which completely cover the mid- and long-wave infrared windows, are the most typical materials used in infrared equipment. However, these classical materials can no longer meet the requirements of high-performance imaging systems, and adding more elements such as Te, Ga, Sb, and Ag to enhance the performance is a reliable way to solve this problem. By analysing the structure and properties of the Ge<sub>20</sub>Se<sub>80–<i>x</i></sub>Te<sub><i>x</i></sub> glass system, the law of its structure and properties evolving with Te content is illustrated. The obtained typical results are shown below. With the increase of Te content, the glass transition temperature (<i>T</i><sub>g</sub>) increases and then decreases, which is caused by the network structure and the average bond energy; the density and refractive index increase in an approximately linear gradient; the Abbe number gradually increases, while the Vickers hardness hardly changes with Te content; the fracture toughness decreases with the Te content increasing. Aiming at the problem that the average coordination number is unable to evaluate the glass systems composed of two or more elements from the same main group, a theoretical bandgap-glass property evaluation system is successfully established. The functional relationships among parameters such as density, refractive index, Abbe number, and fracture toughness, and theoretical band gap are established for Ge<sub>20</sub>Se<sub>80–<i>x</i></sub>Te<sub><i>x</i></sub> glass system as shown in the summary figure, which can be used to rapidly evaluate the glass components and properties.

EFFECTS OF REFRACTIVE INDEX AND ASPECT RATIO ON THE PARTICLE IMAGES IN A LEVITATED DROPLET

A technique using droplets suspended by ultrasound has attracted attention as one of the containerless processing methods. While this can avoid contamination from the container, it is known that ultrasonic levitation creates flow fields inside and outside the droplet. For more precise droplet control, it is desirable to elucidate the internal flow of the droplet, and measurements of the internal flow have been performed using the particle image velocimetry (PIV). The aim of this study is to elucidate the internal flow field behavior by solving optical problems and improving the accuracy of velocity field measurements in levitated droplets. The fluid that is to be investigated is scattered with small tracer particles and illuminated by a laser to capture the flow on a created laser sheet. The curvature distortion is successfully visualized using the PIV approach toward distortion correction using calibration methods. The curvature distortion illustration was performed based on the refractive index and aspect ratio of the simulated droplet in acrylic materials. The fluid flow, affected by droplet curvature and refractive index, has been visualized for both levitated and simulated droplets. The experimental results showed that the droplet curvature can be distorted in two types such as radial and tangential distortions and increase as the refractive index and aspect ratio increases.

Plasmon enhancement of photosensitivity of Ag–chalcogenide glass thin film structures

In this paper, we present the results of studying the features of plasmon- enhanced photostimulated diffusion of silver into thin films of chalcogenide glasses (ChG), in particular, As 2 S 3 and GeSe 2 . To ensure excitation of surface plasmon-polaritons (SPPs) at the interface between silver and ChG films, silver diffraction gratings with periods of 899 and 694 nm were used as substrates. The samples were exposed to the p-polarized radiation of a He-Ne laser (λ = 632.8 nm). The radiation of the same laser, attenuated by two orders of magnitude, was used to detect SPP, which enabled to study the kinetics of photostimulated processes in the thin-layer structure of Ag–ChG. It has been established that in the initial period of exposure, the SPP electromagnetic field significantly enhances the photostimulated flux of silver ions in ChG (by 2-3 times). The photodissolution kinetics of Ag in ChG is defined by the features of the granular structure of the investigated thin chalcogenide films. For the GeSe 2 film with the effective thickness 8 nm, the kinetics of the film refractive index increase caused by silver photodoping is well approximated by a logarithmic dependence. For the Ag–As 2 S 3 structure (the effective thickness of the As 2 S 3 film is 14.8 nm), this kinetics is closer to the linear one; moreover, for photodoping without SPP excitation, the kinetics is somewhat superlinear, while with plasmon excitation, it is sublinear. The main physical mechanism responsible for the acceleration of the process of photostimulated diffusion in the structure under study appears to be an accelerated generation of electron-hole pairs, which takes place in the ChG layer near the interface with the metal, where the SPP electromagnetic field strength is maximum, and/or plasmon- assisted hot carrier generation due to plasmon scattering on the surface of the metal film and subsequent internal photoemission of electrons from silver into chalcogenide.

A-Site Cation Replacement of Hydrazinium Lead Iodide Perovskites by Borane Ammonium Ions: A DFT Calculation.

Organometallic perovskites have become one of the most common multifunctional materials in optoelectronic research fields. This research studies density functional theory calculation on orthorhombic hydrazinium lead iodide (N2 H5 PbI3 ) perovskite by replacing A-site cation with a borane ammonium (BH2 NH3 + ) ion. The perovskite showed a significant structural deformation and an orthorhombic to triclinic phase transition due to A-site ion replacement. The N2 H5 PbI3 perovskite has a band gap of 1.64 eV, suitable for the solar cell absorber layer. The band gap has increased to 2.12 eV after complete A-site ion replacement. All structures showed a high absorption coefficient over 104 cm-1 in the low wavelength region and an increase in refractive index from 2.5 to 2.75 due to ion replacement. All the structures showed high optical conductivity of 1015 s-1 order in the blue wavelength region. These new perovskite structures hold the potential to provide a revolution in optoelectronic research.

Investigations of Nonlinear Optical Properties of Lithium Niobate Crystals

The article is devoted to nonlinear effects in lithium niobate crystals. The possibility of using digital holographic interferograms obtained with the help of laser radiation of different duration at different moments of time for the reconstruction of dynamic phase changes is shown. Holograms were recorded on lithium niobate crystals doped with iron ions in various concentrations using He-Ne and He-Cd lasers, and the diffraction efficiency was calculated. Also, the effect of gamma radiation on the optical properties of LiNbO3 and LiNbO3:Fe crystals was studied. At the same time, it was determined that the band gap of the samples decreases, as a result of which the refractive index, absorption coefficient and photorefractive sensitivity increase several times.

STUDY OF GLASS FORMERS ON BASICS OF OPTICAL ELECTRONEGATIVITY

Concept of electronegativity is used by so many researchers to study Refractive index, Band energy, Dielectric constant, Metallization criterion, Basicity, Oxide ion polarizability, Bond ionicity, Third order non-linear optical susceptibility to study so many glass systems. Here the concept of optical electronegativity is used to study these parameters in glass formers. It is observed that on decreasing the values of optical electronegativity; optical band energy, metallization criterion, and bond ionicity decreases; where as optical dielectric constant, optical basicity, oxide ion polarizability refractive index and third order non linear optical susceptibility increases. All glass forming oxides are according to Pauling's packing rule, Goldschmidt radius ratio rule, Zachariasen's random network theory and rules for formation of glass and Sun’s single bond strength theory. For glass formers radius ratio rc/ra = 0.14-0.40, [except P2O5] and single bond strength greater than 90 Kcal/mol. Key Words: Band energy, Basicity, Optical dielectric constant, Oxide ion polarizability, Refractive index.

Effect of Cobalt Doping on The Structural, Linear and Nonlinear Optical Parameters of Manganese Oxide Thin Layers

AbstractIn this study, undoped and cobalt‐doped manganese oxide Co:Mn3O4 (0, 2, and 4 at%) are elaborated by the spray pyrolysis procedure on glass substrates. The effect of cobalt doping concentrations on the structural, morphological, and optical features (linear and nonlinear) are investigated through the X‐ray diffractometer, Raman spectroscopy, Scanning Electron Microscopy with an attached energy dispersive X‐ray and UV–Vis‐NIR spectrophotometer. The XRD investigations exhibit a polycrystalline tetragonal structure for all Co:Mn3O4 and confirm by Raman results with the distinctive tetragonal mode A1g at 657 cm−1. The SEM images show an increase in roughness as cobalt doping concentration increases. The EDS quantitative analysis revealed the presence of manganese, oxygen, and cobalt. Furthermore, the optical investigation is pursued firstly through the linear optical that showed a decrease in the transmittance, and optical band gap energy as the cobalt concentration increased due to oxygen vacancies and defects and the increase of refractive index from 2.05 to 2.21. Second, the nonlinear optical parameters show a high value of the nonlinear refractive index 3.75 × 10−7 (esu) and the third‐order susceptibility χ3 = 2.2 × 10−8(esu) of Co:Mn3O4(2at%). These values put the Co:Mn3O4(2at%) thin layer as a candidate in the optoelectronic applications as a third‐order nonlinear medium.

Novel polymer/bio-filler composites as alternative eco-friendly materials for energy storage: From solution behavior to solid state analysis

To combat the issue of plastics contamination of the medium, the current technologies are aiming towards development of green materials that are substituting the harmful elements from the disposed devices. This article opens a fresh perspective on designing novel polymer composites by loading hydroxypropyl methylcellulose (HPMC) with bio-derived filler or a mixture of bio-filler and barium titanate (BT) to make alternative eco-compatible materials for energy storage. New insights are extracted from a detailed analysis that correlates the solution behavior to solid state analysis. Rheological data evidence that for attaining uniform dielectric layers spinning times beyond 100 s and spinning speeds below 80 rpm are required. Interfacial compatibility with metal electrodes is checked via experiments of sample wetting on silver or gold layer, showing that adhesion work is increased of 6.24 times for gold support and 5.63 times for silver support, being adequate for capacitor applications. The sample morphology was recorded by scanning electron microscopy, indicating good dispersion of the filler or filler mixture in the bulk cellulose derivative matrix. Refractometry experiments revealed an enhancement of molecular polarizability upon loading, which led to increase of refractive index from 1.52 for neat HPMC to 1.56 for HPMC/oat 40 and 1.57 for HPMC/oat + BT 40, at 489 nm. This is reflected in the increase of the dielectric constant at 1 KHz, namely: 2.19 (HPMC) to 2.79 (HPMC/oat 40) and 3.36 (HPMC/oat + BT 40). The dielectric breakdown is slightly lowered upon loading from 43.8 ∙106 V/m (matrix) to 42.3∙106 V/m (HPMC/oat 40) and 42.0∙106 V/m (HPMC/oat + BT 40). The resulted electric energy density values reach at highest loading the values of 2.198∙104 J/m3 for the sample with oat and 2.635∙104 J/m3 for the sample with oat and BT. This work is a fresh initiative of making eco-compatible dielectrics for future storage systems.

Optical, magneto-optical properties and fiber-drawing ability of tellurite glasses in the TeO2–ZnO–BaO ternary system

The presented work is focused on the optical and magneto-optical characterization of TeO2-ZnO-BaO (TZB) tellurite glasses. We investigated the refractive index and extinction coefficient dispersion by spectroscopic ellipsometry from ultraviolet, λ ≈ 0.193 μm, up to mid-infrared, λ ≈ 25 μm spectral region. Studied glasses exhibited large values of linear (n632 ≈ 1.91–2.09) and non-linear refractive index (n2 ≈ 1.20–2.67×10−11 esu), Verdet constant (V632 ≈ 22–33 radT−1m−1) and optical band gap energy (Eg ≈ 3.7–4.1 eV). The materials characterization revealed that BaO substitution by ZnO leads (at constant content of TeO2) to an increase in linear and nonlinear refractive index as well as Verdet constant while the optical band gap energy decreases. Fiber drawing ability of TeO2–ZnO–BaO glassy system has been demonstrated on 60TeO2–20ZnO–20BaO glass with presented mid-infrared attenuation coefficient. Specific parameters such as dispersion and single oscillator energy, Abbe number, and first-/third-order optical susceptibility are enclosed together with the values of magneto-optic anomaly derived from the calculation of measured dispersion of the refractive index.

Study of Conditional Glass Formers (I) on Basics of Optical Electronegativity

Concept of Electronegativity is used by so many researchers to calculate Refractive index, Band energy, Dielectric constant, Metallization criterion, Basicity, Oxide ion polarizability, Bond ionicity, Third order non-linear optical susceptibility to study the so many glass systems. Here the concept of optical electronegativity is used to study these parameters for conditional glass formers referred as (1) taken from group III (A,B) and IV (A,B); they are Y2O3, HfO2, ZrO2, Sc2O3, TiO2, Al2O3, In2O3, Ga2O3, and SnO2. It is observed that optical band energy, metallization criterion, and bond iconicity decreases; and optical dielectric constant, optical basicity, oxide ion polarizability refractive index and third order non linear optical susceptibility increases. All conditional glass formers (I) oxides are according to Pauling's packing rule, Goldschmidt radius ratio rule, Zachariasen's random network theory, rules for formation of glass and Sun’s single bond strength theory. For conditional glass formers (I) radius ratio rc/ra = 0.40-0.75 and single bond strength greater than 90 Kcal/mol. According to Sun’s, high bond strength oxides are not good glass formers because they themselves do not forms glass; but when they forms small ring in the melt of these materials which result in easy crystallization. Key Words: Refractive index Band energy, Dielectric constant, Metallization criterion, Basicity, Oxide ion polarizability, Bond ionicity, Third order non-liner optical susceptibility.

Structural, optical, and dielectric characteristics of chitosan/hydroxypropyl cellulose‐modified copper vanadate nanoparticles

AbstractChitosan (Cs) and hydroxypropyl cellulose (HPC) blend films were created and incorporated with copper vanadate nanoparticles. The films were characterized using various techniques, including x‐ray diffraction (XRD), attenuated total reflectance‐Fourier transform infrared (ATR‐FTIR), TEM, SEM, UV/vis spectroscopy, dielectric properties, and AC conductivity. The XRD analysis showed that the prepared films had amorphous characteristics. FT‐IR spectra indicated interactions between the Cs/HPC virgin polymers and copper vanadate nanoparticles. TEM analysis showed that the most prevalent size range of the nanoparticles was 20–60 nm. SEM micrographs revealed surface homogeneity at lower copper vanadate nanoparticle contents but increased inhomogeneity with higher contents. The prepared films showed a decrease in the optical energy gap and an increase in refractive index with increasing copper vanadate nanoparticle content. Copper vanadate nanoparticles enhance AC conductivity in Cs/HPC polymer blend. Dielectric analysis proved the suitability of the films for electroactive polymer applications.Highlights The casting process was used to prepare Cs/HPC—copper vanadate NPs films. XRD shows increased amorphousness post‐addition of copper vanadate NPs. SEM images revealed an increase in inhomogeneity with higher contents of copper vanadate NPs. The optical band gap decreased as the content of copper vanadate NPs increased. Copper vanadate nanoparticles greatly improve electrical conductivity and relaxation time.

Solution processed multi-layered thin films of Ge20Sb5S75 and Ge20Sb5Se75 chalcogenide glasses

Solution processed non-toxic Ge20Sb5Se75 chalcogenide glass thin films were deposited using spin-coating method from n-propylamine—methanol solvent mixture in specular optical quality. Optical properties, composition, structure, and chemical resistance were studied in dependence on the annealing temperature. Significant increase of refractive index and chemical resistance caused by thermoinduced structural polymerization and release of organic residua were observed. The high chemical resistance of hard-baked thin films allowed repeated direct depositions by spin-coating, increasing total thickness. Multilayered thin films of amorphous Ge20Sb5Se75 and Ge20Sb5S75 were also successfully prepared by direct deposition for the first time. Solution based deposition of non-toxic Ge20Sb5Se75 thin films in specular optical quality significantly widens the applicability of solution processed chalcogenide glass thin films. Moreover, solution based direct deposition of different glasses on hard-baked thin films opens the way to simple and cost-effective preparation of more sophisticated optical elements (e.g. beam splitters, photonic mirrors).

Contribution of dissolved organic matter to seawater salinity measured by optic refractometer: a case study of DOM extracted from Aoshan Bay

Dissolved organic matter (DOM) in seawater, consisted of a complex mixture of compounds and accounted for about 90% of marine organic carbon, is an important part of the global carbon cycle and also a part of absolute salinity of seawater. As the components of DOM are non-ionized in seawater, electric conductivity measurement cannot observe its contribution to salinity, which could lead to measurement error in salinity. Salinity measurement based on optic refractive index could reveal contribution of all dissolved matters in seawater including both non-ionized and ionized components. In this paper, a comparative study of DOM contribution to the salinity measurement by optic refractive index method and electric conductivity method was carried out for the first time. Adding DOM, extracted from Aoshan Bay, Qingdao, China, into Chinese Standard Seawater, our experimental results showed an increase of optic refractive index at 1.19×10-4 ± 4×10-6 per 1g/kg of DOM, which corresponds to a practical salinity increase of 0.697 ± 0.036 PSU per 1 g/kg of DOM. While, the conductivity of seawater measured by a conductivity-temperature sensor showed a decrease of 0.00065 ± 0.00008 mS/cm per 1 g/kg of DOM, which corresponded to a decrease of salinity at 0.00052 ± 0.00007 PSU per 1 g/kg of DOM. By comparing the optic and electric measurement results, the contribution of non-conductive components in the dissolved organic matters to salinity could be distinguished, which has great significance for the measurement of absolute salinity, global carbon cycle etc.

Terahertz spectroscopy research on motion‐limited molecular chain of random polymethacrylate

AbstractIn this study, an innovative method was used to examine the impact of gamma‐ray irradiation on three specific monomers: methyl methacrylate (MMA), hexyl methacrylate (HMA), and lauryl methacrylate (LMA). The primary objective was to produce corresponding polymers—polymethyl methacrylate (PMMA), polyhexyl methacrylate (PHMA), and poly(lauryl methacrylate) (PLMA). The significance of the research was determined by conducting a thorough analysis of the thermal properties and structural characteristics of these polymers using advanced techniques, including thermogravimetric analysis and differential scanning calorimetry (TGA‐DSC), as well as Fourier transform infrared spectroscopy (FTIR). The results indicated that irradiation at a 30 kGy dose caused distinct decomposition of ester groups within the polymer matrices. Additionally, a clear trend was observed in the maximum exothermic temperature among the three polymers, with PMMA exhibiting the lowest temperature, followed by PLMA, and PHMA with the highest temperature. Surprisingly, when the radiation dose exceeded 30 kGy, PHMA's thermal stability peaked, demonstrating remarkable resistance to further changes. This highlights the crucial role of radiation dosage in adjusting polymer thermal properties. Furthermore, analysis of infrared characteristic peaks identified a critical radiation dose range between 15 and 30 kGy, where polymerization was efficiently promoted without generating extra by‐products, showcasing experimental ingenuity. Lastly, optical properties of the synthesized polymers were explored using THz time‐domain spectroscopy. Results showed intriguing changes in refractive indices following 30 kGy dose irradiation. Specifically, MMA and HMA exhibited moderate refractive index increases, while LMA displayed a significant decrease. Notably, PHMA demonstrated substantial absorption reduction beyond 15 kGy doses, with minimal further changes, highlighting the potential to customize polymer optical properties through controlled irradiation.

Ab Initio Investigation of Electronic and Optical Properties of Cu‐Doped As2S3

The density functional theory with generalized gradient approximation is used to investigate the structural, electronic, and optical properties of Cu0.125As2S3 and Cu0.25As2S3 configurations with copper impurity at c‐face center interstitial site. The AsS bond lengths remain nearly the same but CuS bond lengths decrease with the increase in copper concentration. Both the configurations show n‐type conductivity and strong p–d hybridization in valence and conduction bands. The density of copper d states in the valence band increases with the increase in Cu content. The calculated optical constants are strongly anisotropic up to 10 eV; however, at higher energies the anisotropy diminishes. The broad peaks in the optical constants along || and axes are found in the vicinity of 2 eV. However, the peak heights increase and shift toward lower energy with the increase in copper content. Further, the static dielectric constant, refractive index, and reflectivity increase and the optical bandgap decreases with the increase in copper concentration. The comparison of optical constants shows that Cu0.25As2S3 may be as good choice as Ag0.25As2S3 for optical applications.

Molecular Structure and Properties of Sulfur-Containing High Refractive Index Polymer Optical Materials.

High refractive index polymers (HRIPs) are widely used in lenses, waveguide, antireflective layer and encapsulators, especially the advanced fields of augmented/virtual reality (AR / VR) holographic technology and photoresist for chip manufacturing. In order to meet the needs of different applications, the development of HRIPs focuses not only on the increase in refractive index but also on the balance of other properties. Sulfur-containing high refractive index polymers have received extensive attention from researchers due to their excellent properties. In recent years, not only ultrahigh refractive index sulfur-containing polymers have been continuously developed, but also low dispersion, low birefringence, high transparency, good mechanical properties, and machinability have been studied. The design of HRIPs is generally based on formulas and existing experience. In fact, molecular structure and properties are closely related. Mastering the structure-property relationship helps researchers to develop high refractive index polymer materials with balanced properties. This review briefly introduces the preparation methods of sulfur-containing high refractive index polymers, and summarizes the structure-property relationship between the sulfur-containing molecular structure and optical properties, mechanical properties, thermal properties, etc. Finally, the important role of synergistic effect in the synthesis of HRIPs and the prospect of future research on HRIPs are proposed.

Plasmonic Lattice Modes with High Quality Factor in Inhomogeneous Environment

Plasmonic lattice modes (PLM) with high quality factor is formed by periodic Au hemisphere arrays on the quartz substrates. The formation of PLM is attributed to the coupling between the localized surface plasmon resonance of Au hemispheres and the diffracted waves inside the substrates rather than the diffracted waves in the air. By changing the hemispheres’ size and the arrays’ period, the PLM wavelength is adjustable. It is also found that the refractive index of the substrates has no effect on the quality factor of PLM. As the refractive index increases, the position of the PLM wavelength has a redshift. While the surroundings where periodic Au hemisphere arrays on the quartz substrates are located affect the quality factor of PLM.

Doping effect on optical properties of pure and malachite green doped polyvinylidene fluoride films

The films of pure polyvinylidene fluoride (PVDF) and various concentration of malachite green (MG) doped have been prepared by solution cast method. The absorption spectra recorded by UV-VIS spectrophotometer 1700 Shimadzu. Absorbance versus wavelength spectra of pure and various concentration of MG doped PVDF films were observed in wavelength range 200-800 nm. With increasing malachite green in PVDF, intensity of absorbance edge and refractive index increases.