Glass Prism Research Articles

Effective prism diopter for strabismus measurement: Conversion from anterior Prentice position to posterior parallel position and from glass prism to acrylic prism.

In clinical ophthalmology, prisms, commonly made of glass, are labeled based on the prism diopter (PD) value measured in the anterior Prentice position. However, they are often used in the posterior parallel position for practicality, causing a discrepancy between labeled and effective PD. This study proposes a conversion tool to address this issue. Geometric optical analysis was employed to calculate the effective PD of glass prisms in the posterior parallel position. A lookup table was created to convert the labeled PD of the anterior Prentice position to the effective PD when the prism is used in the posterior parallel position. Clinical data from 162 patients with horizontal strabismus were collected to validate the method. Glass prism measurements, converted to effective PD, were compared with acrylic prism results. The variations were significant in glass prism PD with rotation in the anterior Prentice position but stability in the posterior parallel position. Clinical deviations were larger with glass prisms, especially exceeding 30 PD, compared with acrylic prisms. Converted PD from glass prisms correlated well with acrylic prisms (R2 = 0.94, P = 0.002). The half-width of the 95% limit of agreement was ±12.32 PD. The proposed conversion table is valid, facilitating consistency between clinical and literature-based prism use in different positions and materials.

Ultra-sensitivity of surface plasmon resonance sensor using halide perovskite FASnI3 and 2D materials on Cu thin films

This paper studies a novel surface plasmon resonance (SPR) biosensor using a BK7 glass prism, a copper (Cu) metal plasmonic layer, which combine a halide perovskite (FASnI3) with two-dimensional (2D) materials such as phosphorus black, graphene and TMDC (MoS2, MoSe2, WS2, WSe2) for the detection of breast cancer cells. We have optimized the thickness of each layer in order to obtain maximum sensitivity. A numerical study mainly uses the transfer matrix principle, while the attenuation total reflection method involves examining the reflection properties. The evaluation of SPR biosensor configurations serves to obtain optimal performance. The simulation results indicate that the integration of halide perovskite (FASnI3) and 2D materials into the BK7/Cu/medium sensing structure significantly improves the sensitivity and figure of merit (ZT). The outstanding results in terms of sensor performance characteristics are observed in the BK7/Cu (48 nm)/FASnI3 (5 nm)/BP (0.53 nm) configuration. The figure of merit and sensitivity estimated at 123.11 RIU−1 and 459.28°/RIU, with a notable improvement of 338.45 %.

Strategic approaches to enhance efficiency and commercial feasibility of copper-based surface plasmon resonance sensing

Despite enormous progress in the field of surface plasmon resonance (SPR) imaging sensor technology in the past three decades, noble metals like Au and Ag, despite their drawbacks, continue to be the metals of choice for plasmonic sensing layers. The conventional architecture of the SPR sensor based on gold/silver and glass prism hinders scaling, portability, and industrial manufacturing. In this contribution, we present a novel architecture of SPR sensor using copper on polycarbonate prism as a cost-effective, scalable, and mass-producible alternative. Various optimization techniques, such as interface layer, protective encapsulation, and 2D affinity layer are explored to address the challenges related to the practical application of copper in a plasmonic sensor. Our results show that optimized architectures of SPR sensor based on copper has a sensitivity of 235.01°/RIU. From a quantitative analysis of the interrelationships among various performance parameters, we have derived a comprehensive sensing parameter that integrates signal quality and sensitivity. The proposed architecture of the copper based SPR sensor can lead to inexpensive, compact, and handy probes that do not sacrifice accuracy or reliability.

A Historical Approach to Understanding Differentiation of RYB vs RGB

This article defines the roles of colors and presents their historical development as a fundamental means of expression within artwork. It also introduces color theorists and practices, including the mixing of pigments, a necessary technique for artists-designers in creating tangible results. Modern artists-designers have used these theorists to express themselves in producing an aesthetic experience in the viewer through their artwork, starting with Sir Isaac Newton’s light-spectrum experiments using a glass prism and a beam of white light, and continuing through Johannes Itten’s color-wheel and creative color-matching exercises. This article objective defines the significance of color, its historical development on the basis of earlier perceptual theorists’ findings that color acquires dimension and meaning in response to cultural-historical context or psychological realities. As a result, this paper also explores how color affects our emotions, our psychic and spiritual manifestations. This psychic-spiritual manifestation is revealed through a process of visual perception and experimenting with color and its symbolic meaning. Artists such as Seurat, Munch, Kandinsky, Paul Klee, Josef Albers, Picasso, Joan Miro, or Mark Rothko demonstrated the expressive power of color-pigment. The authors hope that this paper will bring significant discussion, awareness, will assist general readers and academic researchers and truly advance knowledge.

SURFACE PLASMON RESONANCE ANALYSIS FOR BENZENE SENSING MEDIA USING SILVER AND Ta2O5 THIN FILMS

The increasing demand for optical sensors is driven by their wide applications, making surface plasmon resonance (SPR) play a crucial role in this field. In this study, a multilayered thin film consisting of tantalum pentoxide (Ta2O5) and silver (Ag) deposited on a glass prism was used to study SPR. The Ag layer thickness was fixed at 50 nm, while the Ta2O5 layer thickness varied from 0 to 70 nm. The Kretschmann configuration was employed to assess the sensitivity of air and gases with different refractive indices. Therefore, different layer thicknesses along with different wavelengths and angles were investigated. MATLAB software was employed to simulate and analyze SPR with a half-sphere prism to extend the incident angle. The simulation conditions with Fresnel equations were used to calculate the reflectivity and transmittance coefficients for the studied sample. The results revealed that the best output was at a Ta2O5 thickness of 50 nm to get optimal full width at half maximum of 2.4 and sensitivity factor of 162.5. This device works in the visible and infrared regions.

Incandescent Lamp from Black Body Perspective

The incandescent lamp from black body perspective was investigated using commercial lamps of various watts. The major component of the incandescent lamp is the tungsten filament. The resistance of the tungsten filament was measured using a digital multimeter at an initial laboratory temperature. Light produced from lamp was separated into visible colours by an equilateral triangular glass prism. Deduced resistances were used to obtain equivalent temperatures by power-law parameterization. The Wien’s displacement law was used to estimate Peak wavelengths at different temperatures. The diameter of the tungsten was measured after dissecting the lamp, and this was used to determine its cross-sectional area. Both Wien’s displacement law and Stefan-Boltzmann expressions were applied in determining the filament’s spectral emissive power (SEP) in comparison with that of the visible spectrum. Planck’s graph of intensity using peak wavelength of tungsten filament as reference was juxtaposed with the intensity of visible spectrum using OriginPro 2016 SR0 b9.3.226. The maximum temperature attained was 2852.87 K with (SEP) of 1478955.24 Wm-2 for the 200W lamp. For the 100W lamp, the (SEP) obtained was 749347.9078 Wm-2 at 2489.14 K. Both temperatures, and even as low as 1250 K, were in agreement with Wien’s displacement law. The percentage estimation of visible spectrum in the radiation was about fourteen percent (14 %) while the rest was infra red radiation. This low visible light produced may be as a result of the non-ideal black body nature of the tungsten filament; and so, the incandescent lamp may be considered a quasi-black body.

Measurements of Sensitivity and Figure of Merit for Noble Metals (Au, Ag, Cu) Thin Film Biosensor Based on SPR Simulation Characterizations

In this paper, we investigate the influence of varying the thickness of noble metals, namely gold (Au), silver (Ag) and copper (Cu), and the incident light wavelength on the surface plasmon resonance (SPR) properties for biosensor applications. Our analysis employs the Fresnel equations to examine the absorption characteristics of these metals when the refractive index shifts by (0.03,0.06). We explore metal layer thicknesses ranging from [Formula: see text][Formula: see text]nm and incident light wavelengths of [Formula: see text] and 600[Formula: see text]nm, with incident angles ([Formula: see text]) ranging from 0∘ to 90∘. Utilizing simulation analysis in MATLAB, we simulate the SPR responses of these metals when deposited on BK-7 glass prisms, with air as the surrounding medium. Our calculations reveal the absorption properties of Au, Ag and Cu, as indicated by the angle of incidence ([Formula: see text]SPR). Our findings demonstrate that the highest absorption occurs with copper (Cu) at [Formula: see text] (a.u.) for [Formula: see text][Formula: see text]nm and [Formula: see text][Formula: see text]nm. When [Formula: see text] is adjusted to 600[Formula: see text]nm, gold (Au) exhibits the highest absorption (A) at 0.997 (a.u.) with a thickness of [Formula: see text][Formula: see text]nm. Additionally, we calculate sensitivity values for all three metals, with copper (Cu) yielding the highest sensitivity of 101.6 Reflected Index Units (RIU-1) for both [Formula: see text] and 600[Formula: see text]nm. Furthermore, we compute the Figure Of Merit (FOM), with silver (Ag) achieving the highest FOM of 443 at [Formula: see text][Formula: see text]nm and 451 at [Formula: see text][Formula: see text]nm. These results provide important signs about noble metals’ SPR properties in biosensing, and serve as guides for optimizing the biosensors.

Surface exciton polariton enhanced Goos-Hänchen and Imbert-Fedorov shifts and their applications in refractive index sensing.

The spatial and angular Goos-Hänchen shifts (GHSs) and Imbert-Fedorov shifts (IFSs) are theoretically investigated in a modified Kretschmann-Raether configuration consisting of glass prism, J-aggregate cyanine dye, and air. With the excitation of surface excitation polaritons (SEPs), the spatial and angular GHSs and IFSs for the transverse magnetic polarized light are strongly enhanced around the resonant angle of SEP. A highly sensitive gas sensor based on the SEP enhanced GHS (or IFS) is proposed, which exhibits the refractive index sensitivity on the order of 106λ/RIU (or 105λ/RIU) (λ: illumination wavelength; RIU: refractive index unit) for the GHS- (or IFS-) based gas sensor, respectively.

Development of an arrayed ultrasonic sensor using surface plasmon resonance (SPR)

Surface plasmon resonance (SPR) ultrasonic sensors are non-resonant and expected to show flat frequency response over a wide frequency range. Then, the sensors seem suitable for the detection of photoacoustic waves. We have developed a simple glass prism SPR sensor with thin Ag layer (deposited by an electron beam evaporator) and checked the frequency response as a function of Ag area diameter. The diameter of 1 mm was sufficient to obtain better frequency response than that of the calibrated needle transducer in the range of 2.5 to 7.0 MHz. By covering a very thin Au film on the Ag layer, we succeeded in longer working time (>6 months) of the sensor. An array-type SPR sensor (5 × 5, diameter of each sensor 1 mm) has also been fabricated to evaluate pressure distribution of ultrasonic waves. The response of each sensor was similar, telling the high reproducibility of the sensor fabrication.

Study the Optical Properties of Noble Metal (Au, Ag, and Cu) Thin Film Biosensors Based on Surface Plasmon Resonance Performance by a Simulation Program

In this work, we studied the effect noble metal thicknesses, namely gold (Au), silver (Ag), and copper (Cu) on the surface plasmon resonance (SPR) characteristics for sensitive optical sensor and biosensor applications. SPR spectra for Au, Ag and Cu were widely studied in the Fresnel equation to calculate the total reflection, the wavelength ([Formula: see text] range from 500 nm to 700 nm with the angle of incidence ([Formula: see text] ranging from 0∘ to 90∘ and thickness of the film ([Formula: see text] reaching from 30 nm to 70 nm. Analysis simulation (in MATLAB) has been made for SPR of three metals placed on the N_LASF9 glass prism and the sensing medium is the air. The properties of the angle of resonance [Formula: see text] have been calculated from plotted reflectance via incident angle [Formula: see text]. The results give efficient detection in a change of reflection ([Formula: see text] and full half width maximum FWHM. The minimum reflection was obtained (0.003 a.u.) at wavelength 700 nm and thickness [Formula: see text]= 50 nm for gold Au at [Formula: see text] = 0.0. The best FWHM was recorded at the wavelength (500 nm) at thickness (70 nm) for silver at [Formula: see text] = 0.0, which was equal (0.1 nm).

Terahertz characterization of combined pressure-shear shock loaded aromatic polyurea

Realistic shock loading scenarios imply combined, multiaxial stress states, where the mechanically induced energy competes for failing the material intrinsically due to cohesive failures. Under shock loading, failure encompasses various modes, including spallation, shear bands, microcracking, morphological alteration, phase transformation, and plastic deformation. However, elucidating failure in high strain loading conditions challenges the state-of-the-art characterization due to the disparity interfacing different loading and measurement techniques. This research used a novel spectro-mechanical characterization setup, integrating bulk terahertz spectroscopy synchronized in real-time with mixed-mode laser-induced shock waves. The latter was used to submit polyurea elastomers to concurrent pressure and shear waves by saddling a thin polymer sheet on the hypotenuse of a glass prism. Hence, the laser-induced pressure shock waves underwent simultaneous mode conversion at the glass-polyurea interface at the hypotenuse of the glass prism, effectively submitting the sample to tunable amplitude pressure-shear shock waves. The terahertz spectroscopy, operating in the right-angle reflection configuration, was modified to probe predetermined spots on the polyurea samples at different stress states (adjusted by changing the illumination energy) in a three-step sequence: before, during, and after shock loading. The shock-loaded polyurea samples were also characterized using the optical and scanning electron microscopes, revealing compression-shear and tensile-shear failure modes, including surface depression, nucleation of micro-voids and microcracks, and formation of small planes. The induced stress state based on the illumination energy was quantified using an accompanying finite element simulation, resulting in completing the quasi-isentropic behavior of polyurea elastomers, which was found to be in good agreement with previous experimental data from the plate impact experiments and the predictions based on the Lennard-Jones potential. Time domain analysis of terahertz data, using temporal shifting, hysteresis, and dynamic time warping based on the sum of the Euclidean distances between signal pairs, affirmed the microscopy observations while shedding insights on the elastic and plastic deformations and the reversible conformational changes. Irreversible changes to the macromolecule were also detected using the terahertz data spectral analysis. The current results establish a new experimental framework for fundamentally characterizing polymers and their composites at ultrahigh strain rate loading conditions.

SPR-Based refractive index sensor using BaTiO3 and WS2 with Al-Ni bimetal for glucose sensing

In this work, we propose a high-performance surface plasmon resonance (SPR)-based refractive index biosensor to determine the glucose concentration in the urine samples. To achieve the most efficient design for the sensor, four possible designs have been investigated. The proposed design of the sensor uses the Kretschmann configuration, which consists of a BK7 glass prism with Aluminum (Al) and Nickel (Ni) metallic layers separated by a dielectric layer of barium titanate (), and a 2D material tungsten disulfide () layer placed above the Ni layer. The dielectric layer of is used to enhance the shift in the resonance angle and to increase the absorption of the biomolecules, which results in an increase in the sensitivity of the sensor. The performance of the sensor has been numerically investigated using the transfer matrix method at wavelength. Minimum reflectance at resonance is studied to show the coupling strength of the incident light with the surface plasmons. The thicknesses of the Al and Ni metallic layers have been optimized for maximum sensitivity and minimum reflectance at the resonance. The performance of the proposed sensor has been investigated to obtain sensitivity for different glucose concentrations in the urine samples. The sensor has a sensitivity of for glucose concentration in the range The corresponding glucose concentration sensitivity is 0.4 The proposed study would be helpful in designing the refractive index-based biosensor for medical diagnostics applications.

THE INFLUENCE OF THE STRUCTURAL PARAMETERS OF THE MATERIALS OF THE SENSITIVE ELEMENT OF THE OPTICAL SENSOR ON ITS SENSORY PROPERTIES

The sensor element of an optical sensor based on surface plasmon resonance is investigated in the paper. In particular, the influence of the components of the sensor element on its sensor properties by modeling design options. The Kretschmann configuration was chosen as the model, which is a glass prism with a multilayer nanoscale structure applied to one face. It was established that the material of the prism affects only the resonance angle of the structure. The thickness of nanoscale gold and silver films varied from 1 to 100 nm. The minimum value of the coefficient was obtained when the thickness of the gold and silver nanoscale films was 50 nm and 45 nm, respectively. The thickness of the silicon dioxide film varied from 10 to 150 nm. In the Au – SiO2 structure, the addition of silicon dioxide improved the optical properties of the multilayer structure. The minimum value of the reflection coefficient has decreased, but the thickness of the silicon dioxide is 3 nm. When the thickness of the dielectric layer increases, the optical properties of the structure deteriorate. The structure of the sensitive element, which uses a nanosized silver film, almost does not change its optical properties when adding a layer of SiO2, its thickness can reach 50 nm.

Theoretical study of perovskite nano material based surface plasmon resonance biosensor for cancers cell detection

The present study reports screening of cancer cells at the earliest stages using prism coupling-based surface plasmon resonance biosensors in a theoretical manner. The SPR sensors designed on Kretschmann configuration consisting of several layers like silver (Ag) metal, beryllium oxide (BeO) and hetero-structure BlueP/WSe2 layer deposited over BK7 glass prism. For maximum light absorption, a perovskite nano material, barium titanate (BaTiO3) layer is placed between BeO and hetero-structure BlueP/WSe2 to enhance the angular sensitivity. The light of 633 nm wavelength has been used for excitation of surface plasmon at metal dielectric interface. The refractive index of cancer cells lies between 1.360 and 1. 400. The optimized angular sensitivity of 216°/RIU and 360°/RIU for PCI-2 (normal, adrenal gland cancer), 248°/RIU and 254°/RIU for MDA-MB-231(normal, breast cancer cell) as well as 248°/RIU and 254°/RIU for MCF-7 (normal, breast cancer cell) respectively has been obtained. The maximum optimized angular sensitivity for adrenal gland cancer is 360°/RIU on employing perovskite layer. The sensor offers excellent performance parameters and covers wide range of refractive index sensing.

Development of a biosensor based on a surface plasmon resonance structure comprising strontium titanate, graphene and affinity layers for malaria diagnosis

This paper investigates the numerical analysis of a highly performed surface plasmon resonance (SPRE)-based sensor employing a hybrid structure of SrTiO3 (STO) and graphene for rapid detection of malaria. The investigation is performed using the angular interrogation technique and transfer matrix method. The SPRE device has a glass prism, silver (Ag), STO, graphene, affinity layer and sensing medium (SGM). Four coupling prisms are examined and we found the prism N-FK51A corresponds to the highest sensitivity. The sensitivity of the structure N-FK51A/Ag/STO/graphene/affinity layer/SGM is found to be 205.405, 222.222 and [Formula: see text]/RIU for Schizont, Trophozoite and Ring malaria stages. The layer thicknesses are then optimized and it is found that the proposed SPRE sensor can achieve a sensitivity of 278.378, 227.027 and [Formula: see text]/RIU for Schizont, Trophozoite and Ring malaria stages with 30 nm (silver), 1[Formula: see text]nm (STO), mono-sheet of graphene and 5[Formula: see text]nm of the affinity layer. These findings demonstrate that the proposed method and structure can be used efficiently for biomedical applications.

Histologic Examination of Vocal Fold Mucosal Wave and Vibration.

Despite gross anatomic and histologic differences between human and canine vocal folds, similar wave patterns have been described yet not fully characterized. We reconstructed vocal fold (VF) vibration in a canine hemilarynx and performed histologic examination of the same vocal fold. We demonstrate comparable wave patterns while exploring the importance of certain anatomic architectures. An in vivo canine hemilarynx was phonated against a glass prism at low and high muscle activation conditions. Vibration was captured using high-speed video, and trajectories of VF medial surface tattooed landmarks were 3D-reconstructed. The method of empirical eigenfunctions was used to capture the essential dynamics of vibratory movement. Histologic examination of the hemilarynx was performed. Oscillation patterns were highly similar between the in vivo canine and previous reports of ex vivo human models. The two most dominant eigenfunctions comprised over 90% of total variance of movement, representing opening/closing and convergent/divergent movement patterns, respectively. We demonstrate a vertical phase difference during the glottal cycle. The time delay between the inferior and superior VF was greater during opening than closing for both activation conditions. Histological examination of canine VF showed not only a thicker lamina propria layer superiorly but also a distinct pattern of thyroarytenoid muscle fibers and fascicles as described in human studies. Histologic and vibratory examination of the canine vocal fold demonstrated human vocal fold vibratory patterns despite certain microstructural differences. This study suggests that the multilayered lamina propria may not be fundamental to vibratory patterns necessary for human-like voice production. NA (Basic science study) Laryngoscope, 134:264-271, 2024.

Terahertz Generation by Beating Laser Driven Plasmons in Graphene Embedded Metal Film

A modified ATR configuration, comprising a glass prism embedded by metal film and graphene, is proposed as a suitable nonlinear medium for laser beat wave terahertz generation. Two lasers, launched on the prism at SPR (surface plasmon resonance) angle, get linearly mode converted into surface plasma waves (SPWs) of much higher amplitude. The SPWs exert a beat frequency ponderomotive force on free electrons of metal film and graphene. The ensued nonlinear current drives beat frequency THz plasmons. A surface ripple on graphene or metal assists phase matching and resonantly enhances the THz field amplitude.

A surface plasmon resonance nanostructure containing graphene and BaTiO3 layers for sensitive defection of organic compounds.

Organic compound-based sensors are used in a variety of significant fields, including medical research, azeotropic calibration, vegetable oil extraction, the shoe industry and geothermal power plants. Here, a high-performance, two-dimensional material-based organic compound sensor has been proposed using a surface plasmon resonance (SPR) nanostructure consisting of a BK7 glass prism, Ag, BaTiO3, Ag, graphene and sensing layer. The reflectivity curves of the SPR device have been investigated when the sensing media are Pentane, n-Hexane, n-Heptane and n-Octane. The thickness of the BaTiO3 layer and the number of graphene sheets have been optimized to maximize the sensitivity. The highest sensitivity attained is 220.83 deg/RIU for n-Octane with 45 nm silver/10 nm BaTiO3/8 nm silver and four layers of graphene. We believe that the SPR-based sensors are simple and can replace the spectrometry, chromatography and electrochemical based sensors. The proposed design is extremely effective for diverse applications in biological, industrial and chemical detection because of its simple structure and great performance.

Spectral focusing-based stimulated Raman scattering microscopy using compact glass blocks for adjustable dispersion.

Spectral focusing is a well-established technique for increasing spectral resolution in coherent Raman scattering microscopy. However, current methods for tuning optical chirp in setups using spectral focusing, such as glass rods, gratings, and prisms, are very cumbersome, time-consuming to use, and difficult to align, all of which limit more widespread use of the spectral focusing technique. Here, we report a stimulated Raman scattering (SRS) configuration which can rapidly tune optical chirp by utilizing compact adjustable-dispersion TIH53 glass blocks. By varying the height of the blocks, the number of bounces in the blocks and therefore path length of the pulses through the glass can be quickly modulated, allowing for a convenient method of adjusting chirp with almost no necessary realignment. To demonstrate the flexibility of this configuration, we characterize our system's signal-to-noise ratio and spectral resolution at different chirp values and perform imaging in both the carbon-hydrogen stretching region (MCF-7 cells) and fingerprint region (prostate cores). Our findings show that adjustable-dispersion glass blocks allow the user to effortlessly modify their optical system to suit their imaging requirements. These blocks can be used to significantly simplify and miniaturize experimental configurations utilizing spectral focusing.

Silver Prism Interface Plasmon Resonance for Biosensor in Ir-Visible Spectrum Region

The performance of a surface Plasmon resonance (SPR) sensor with silver film was demonstrated. The Kretschmann setup's evanescent field, which can activate the sensor. The sensitivity and FWHM of the SPR sensor drop as the thickness of the silver layer in the metallic film increases. Using water as a sensing medium, it can create a simulation model at various thicknesses of the silver layers placed on the semicircular glass prism D-ZLAF50 with a thickness of dAg = 10–80 nm. The proposed sensor can function at wavelengths of up to 600,700nm in the visible area and the infrared region at wavelengths of 900 & 1000 nm. Optimum sensitivity (S = 100–140) may be observed in the visible and infrared spectrum with thicknesses ranging from dAg = (10–80) nm , ∆n = 0.1. At silver layer thicknesses, the values of SPR dip length and FWHM are excellent (40–60 nm).