Glass Prism Research Articles

Making a Simple Prism as an Alternative Physics Practicum Tools

Refraction of light occurs due to the difference in the speed of light in the two mediums where the speed of light in a dense medium is smaller than the speed of light in a less dense medium. One of the refraction phenomena also occurs in prism glass. Prisms help scatter incoming light from monochromatic light sources. To prove this, refraction experiments can be carried out using a prism. Where the prism used is made manually using used glass made of acrylic. The prism that is made is then filled with water on the inside and a test is carried out to determine the refraction and the value of the angle of deviation. Based on the results obtained, the refraction of the prism glass made in where a beam of light that passes through the prism is deflected from its original direction, while the angle of deviation of the rays is proportional to the angle of incidence

Spatial coupling efficiency of collimators based on gradient-index lens with an angle polish

As high coupling efficiency and return loss are crucial in fiber-optic transmission systems, they have attracted widespread attention. This study proposes a ray-transfer matrix-based mathematical analysis method and experimentally demonstrates a collimator based on a gradient-index lens with an angle polish. The propagation characteristics and coupling mechanisms of the collimators are introduced. A beam-steering technology based on a wedge prism and flat glass is proposed to improve the coupling efficiency of the Gaussian beam using collimators. The proposed method is validated via simulation and experiment. The results are significant in free-space optical communication, optical signal processing, and optical fiber connectors.

Students’ knowledge on the identification and use of physics laboratory apparatus in post-basic schools in Ilorin, Nigeria

Physics teaching and learning theoretically may not achieve its full objectives without the integration of laboratory activities. The study measures post-basic school students’ knowledge of identification and use of physics laboratory apparatus so as to ascertain their readiness for external examinations. The method adopted was descriptive survey of cross sectional type of research that enables data collection through measurement tool. One hundred and forty-three physics students’ check-lists were analysed using descriptive statistics (frequency count and simple percentage). The findings of this study revealed that out of the commonly identified physics laboratory apparatus, students high strength was recorded in identifying the apparatus like retort stand, weight/mass, meter rule, pendulum bob, knife edge, optical pin, glass prism and test tube. The students show high strength in stating correct use of the apparatus like meter rule, stop watch, beaker, ammeter and voltmeter. It is recommended that pasting and displaying the apparatus pictures, name of the apparatus, its uses/functions beside it in the physics laboratory wall and early exposure of the students to laboratory activities will help the students in apparatus identification and prepare them for external examinations.

Strong Coupling between Surface Plasmon Resonance and Exciton of Labeled Protein-Dye Complex for Immunosensing Applications.

In this study, we present an analysis of the optical response of strong coupling between SPR and labeled proteins. We demonstrate a sensing methodology that allows to evaluate the protein mass adsorbed to the gold's surface from the Rabi gap, which is a direct consequence of the strong light-matter interaction between surface plasmon polariton and dye exciton of labeled protein. The total internal reflection ellipsometry optical configuration was used for simulation of the optical response for adsorption of HSA-Alexa633 dye-labeled protein to a thin gold layer onto the glass prism. It was shown that Rabi oscillations had parabolic dependence on the number of labeled proteins attached to the sensor surface; however, for photonic-plasmonic systems in real experimental conditions, the range of the Rabi energy is rather narrow, thus it can be linearly approximated. This approach based on the strong coupling effect paves the alternative way for detection and monitoring of the interaction of the proteins on the transducer surface through the change of coupling strengths between plasmonic resonance and the protein-dye complex.

A novel cantenna based demonstration of frustrated total internal reflection as an analog for quantum tunnelling

We use a ‘Cantenna’ (portmanteau of ‘Can’ and ‘Antenna’), which is a unidirectional homemade waveguide, coupled to a standard readily available, 2.4 GHz Wi-Fi router as a source of microwaves to demonstrate Frustrated Total Internal reflection (FTIR) using paraffin-wax prisms. This largely inexpensive experiment provides an opportunity to demonstrate a process closely analogous to quantum tunnelling in an undergraduate physics lab. FTIR is often demonstrated with glass prisms and lasers, which may not allow for an intuitive understanding of evanescent waves and tunnelling. Wi-Fi signals with a wavelength of 12.5 cm, and large maneuverable prisms, allow the length of the ‘barrier’ to be changed in a tactile way where measurements could be taken with tools available in a standard physics lab.

Highly sensitive surface plasmon resonance sensor for refractive index detection of Helicobacter Pylori

Helicobacter Pylori (H-Pylori) is gram-negative and spiral micro-organism that is responsible for its colonization in gastric microniche. The outcome of recent studies indicates that the development of H-Pylori in human bodies results in peptic ulcers, gastric mucosa, and gastric cancer. Therefore, on-time diagnosis of H-Pylori infection is very important to overcome its adverse effects. In this work, we have adopted the surface plasmon resonance (SPR) sensor for the detection of H-Pylori infection in human bodies. The SPR phenomenon is initiated by placing a 40–50 nm thick layer of gold nanoparticles on the flat surface of the glass prism. Four different configurations are designed by immobilizing a layer of biocompatible materials. Probe 1, 2, 3, and 4 are designed by immobilizing the layers of silicon oxynitride (SiON), molybdenum oxide (MoS2), graphene oxide (GO), and graphene, respectively. Added to this, the specificity of all the sensor structures is attained by functionalizing them with a 0.11 nm thick layer of urease enzyme, which oxidizes only in the presence of H-Pylori. Thereafter, the sensing analysis of all the sensor probes is done in a wide range of refractive index (RI) from 1.3227 to 1.3382 which corresponds to the RI of human urine in presence of H-Pylori. The performance analysis of the sensor is done in the terms of sensitivity, detection accuracy (DA), quality factor (QF), the figure of merit (FoM), and dip of a figure of Merit (DFoM). Added to this, the signal propagation through all the sensor structure is analyzed by using two-dimensional finite-difference-time-domain (FDTD) method-based tool.

High-efficiency bismuth borate-based optical parametric chirped pulse amplifier with approximately 2.1 mJ, 38 fs output pulses at approximately 2150 nm

Abstract We present a compact and cost-effective mJ-level femtosecond laser system operating at a center wavelength of approximately 2.15 μm. An affordable two-stage ytterbium-doped yttrium aluminum garnet (Yb:YAG) chirped pulse amplifier provides more than 10 mJ, approximately 1.2 ps pulses at 1030 nm to pump a three-stage optical parametric chirped pulse amplifier (OPCPA) based on bismuth borate crystals and to drive the supercontinuum seed in the YAG crystal. The energy of the amplified pulses in the wavelength range of 1.95–2.4 μm reached 2.25 mJ with a pump-to-signal conversion efficiency of approximately 25% in the last OPCPA stage. These pulses were compressed to 38 fs in a pair of Suprasil 300 glass prisms.

Calculate The Resonance Angle of Surface Plasmon Resonance Gold film Configured with Kretschmann

The current work includes measurements of the resonance angle and reflectance for p-polarization of the electric field by using the Fresnel equation at a given length. Gold's surface plasmon wave can be seen at the metal-to-air boundary. We try to determine the greatest (SPR) angle for a metal thin layer that is most suitable for the surface plasmon excitation while stimulated by a laser. SPR was performed of a single film of gold placed on a glass prism; there are SPR modes in this structure, which match the surface plasmon. We also suggest that the SPR mode associated with the Au surface, which is extremely sensitive to changes in the surrounding environment, particularly (dielectric). A few considerations to be taken into account to attain the SPR, like the incident angle of light rays addressed and analyzed for the purpose of finding the essential value for the plasmon to be emerge; the gold/air resonance angle. Furthermore, we can compare our result with other work, which was performed by using the Finite-Element-Method (FEM), the simulation is done by FDTD (Finite Difference Time Domain) software. SPR was applied in a variety of domains, containing biomedicine science, optics, biomedicine, photo-thermal plasmon, and health.

Surface plasmon resonance sensing in the advanced physics laboratory

We present a set of experiments and computations suitable for introducing upper-level undergraduate physics and engineering students to the interdisciplinary field of nanoplasmonics for periods ranging from a week-long advanced laboratory session to a summer research project. The end product is a tunable optofluidic device capable of detecting changes in a fluid medium as low as 0.002 refractive index units. The sensing element—a thin gold film on a glass prism coupled to a microfluidic cell—owes its sensitivity to the bound nature of the surface plasmon–polariton waves that are resonantly excited by evanescently coupled light at the gold–fluid interface. Pedagogically, surface plasmon resonance (SPR) sensing immerses students in the rich physics of nanoscale optics and evanescent waves in constructing and operating a precision apparatus and in developing theoretical, analytical, and numerical models to aid both in the physical understanding and engineering optimization of the SPR sensor.

Caustic of colors in Newton's prism.

A single ray of white light, incident on a glass prism, emerges as a family of diverging rays, parameterized by their colors. These originate from a virtual caustic (envelope of colored rays) inside the prism, rather than a focal point. The "caustic of colors" is a singularity different from the familiar colored caustics (incoherent superpositions of monochromatic ray/wave families that themselves possess caustics). Weak dispersion enables analytical approximations: completely describing the virtual caustic, and rendering to simulate its visual colors. The caustic region is very small; observing it with a beam narrow enough to resolve its colors would require a meter-sized prism. Observability depends on the third power of dispersion, so the caustic, though not its colors, might be detectable by extension outside the visual range.

Visualization analysis of temperature distribution in the cavity of conventional PPS and high-thermal-conductivity PPS during the filling stage of injection molding

Abstract As a highly thermally conductive PPS that is lightweight and has excellent heat dissipation is expected to be applied in various products, its peculiar filling behavior can cause molding defects such as short shots and surface cracks. To address these challenges, it is important to elucidate the filling behavior and clarify the effects of cavity shape and molding conditions. Thus, we intend to visualize the filling behavior of the high-thermal-conductivity PPS. To achieve this goal, we develop an in-process visualization system to reveal both the thermal and kinetic behaviors of the resin while it fills the cavity. In the system, a sapphire prism glass is utilized in the mold for visualization because it exhibits high strength, high heat conduction, and high infrared transmittance. A high-speed visible camera for kinetic behavior and an infrared camera for thermal behavior are utilized. With the developed system, we successfully obtained for the first time the filling behavior of high-thermal-conductivity PPS. Visualization experiments prove that the temperature of the conventional PPS gradually decreases from the tip to the rear of the flow. However, the temperature of the high-thermal-conductivity PPS drops sharply from the tip of the flow to the rear, and breakage at the flow front near the cavity wall is generated. Our interpretation is that the flow front near the cavity wall can be easily broken when it is stretched, because the ductility of the high-thermal-conductivity PPS largely decreases because of the rapid temperature drop. To suppress the formation of this breakage, we modify the cavity shape and molding conditions, and verify its suppression effect.

Surface Plasmon Resonance (SPR) Simulation of a Gold-Bismuth Bi-layer Gas Sensor

The features of plasmonic surface frequency sensor technology, such as the small number of sensor samples required, electromagnetic interference, and high sensitivity, have been found to be highly important.. In this paper, a simulation program was created in Matlab_b2018 by adopting Fresnel equations for calculating the reflectivity of the electromagnetic wave between different media. A surface plasmon resonance sensor based on electromagnetic wavelengths within the range (100 nm to 1000 nm) has been proposed. The transfer matrix was used for a system consisting of four different media. The first medium is a semicircular BK7 glass prism, the second medium is a gold layer (40 nm thick), then a bismuth layer of variable thicknes(10–80) nm, and the last medium is air as the sensing medium. The surface plasmon resonance (SPR) technique was adopted based on the Kretschmann configuration in the simulation of the proposed system. The simulation results showed that there is no SPR within the range of wavelengths (100-500nm), while SPR appears in the visible region and in the IR region at wavelengths (900 and 1000nm). The SPR phenomenon starts to weaken gradually with an increase in the thickness of the bismuth layer. The full width at half maximum (FWHM) decreases with the decrease of thickness of bismuth layer. The best value for it is (10) at thickness (d=10 nm) and wavelength (900 nm). While the height (H) of the SPR dip increased, with the best value of (0.95) at thickness (d=10 nm) and wavelength (700 nm). Also, the sensitivity increased with increasing the bismuth layer thickness at wavelengths (700 , 800, and 1000 ) nm. The highest obtained sensitivity(S) was (112.5 deg/RIU).

Effect of the Thickness of Nanoscale Layers of the Metal-Dielectric Structure on Its Optical Characteristics

A biosensor is a device which uses a mixture of biological and physicochemical components to detect molecular-level interactions. Essentially, biosensors detect the change in physical properties which occur when an immobilized biological molecule, such as an antibody or a protein, binds to their target analyte. A number of methods have been developed to determine interactions between bioreceptors and their analytes, many of which are based on the principle of Surface Plasmon Resonance, or SPR. The ubiquity of SPR comes from its inherent advantages; it allows real time, highly sensitive monitoring of a wide range of molecular interactions, without the requirement for additional labelling of samples. Surface Plasmon Resonance is caused by the interaction of electromagnetic radiation and the free-flowing cloud of electrons within a metal, a process which induces electromagnetic waves and, under certain conditions, resonance effects. Alterations in the physical conditions at the surface have a significant effect on this resonance, and the detection of these changes form the basis of the SPR biosensor. In the work, the effect of the thickness of the layers of the metal-dielectric structure on its optical characteristics was studied. The simulation was carried out for the Krechman configuration, which is a glass prism on which a multilayer metal-dielectric structure is applied. AuSiO2 was used as a metal-dielectric structure, and a laser beam with a wavelength of 633 nm was used as a source of external electromagnetic radiation. The thickness of the gold film varied from 1 to 60 nanometers. The lowest value of the reflection coefficient is reached at a thickness of 50 nm. The thickness of the silicon dioxide film varied from 1 to 30 nm. When the thickness of the dielectric layer is up to 10 nm, its influence on the optical characteristics is insignificant. Macroscopic values of parameters were used in the study, but it is known that real parameters differ greatly from macroscopic ones. To increase the accuracy of modeling the sensor element in further studies, it will be necessary to take into account dimensional changes in the optical parameters of the nanosized metal component in the structure of the sensor element.

Simulation study to improve the sensitivity of surface plasmon resonance sensor by using ferric oxide, nickel and antimonene nanomaterials

In the present paper, a simulation work has been done to study about a hypersensitive Surface Plasmon Resonance (SPR) based sensor device created by the angular interrogation method based on Attenuated Total Reflection (ATR) phenomenon. The numerical analysis has been done by the method of transfer matrix and a plane polarised source of light of wavelength 633 nm approx (632.8 nm wavelength of He-Ne laser) has been used. In this device configuration, glass prism of Calcium fluoride (CaF2) has been used with Silver (Ag) metal using Kretschmann configuration, a diamagnetic material nanosheets of ferric oxide (Fe2O3), nickel (Ni) and a 2D material antimonene is used as a polymeric structure. All the important performing parameters of SPR sensor such as sensitivity, detection accuracy, quality factor has been calculated for different device configuration of SPR sensor. Fe2O3 and Ag layer thickness has been optimized by using genetic algorithms to obtain the highest sensitivity. The configuration gives the highest sensitivity 310°RIU−1 of projected SPR sensor when sensing medium RI varies from 1.330 to 1.335. For proposed design of SPR sensor the sensitivity and FWHM are high as compared to the conventional SPR senor having FWHM value 3.4995 (deg.). For the proposed device configuration bilayer of Ni and antimonene has been used as a polymeric substance to improve the sensitivity and protect device from corrosion. Penetration depth value of 110.5 nm and 3D plot of transverse electric (TM) field intensity has also been plotted. The numerical simulation is based on transfer matrix method and Fresnel equations and the used softwares are MATLAB and COMSOL multiphysics software. The proposed SPR sensor helps to detect the liquid analytes in the field of biomedical and environmental application.

An optical sensor combining surface plasmon resonance, light extinction, and near-critical angle reflection, for thin liquid film biochemical sensing

We present a novel and low-cost optical sensor to obtain at the same time, fast and label-free optical information such as reflectivity, refractive index and extinction coefficient of biochemical samples. The sensor measures in around one minute optical internal reflectivity as a function of the angle of incidence at the interface between a glass prism covered by a gold nanofilm (≈20 nm) in contact with a liquid sample (≈10 µL). The nanofilm is thin enough that a large fraction of the incident light transmits through it at angles of incidence below the critical angle set by the prism and sample refractive indices (≈ 61°), but thick enough to present a Surface Plasmon Resonance dip for angles of incidence beyond that critical angle. The calculated sensitivity of SPR to the surface refractive index is 168.35 deg/RIU. We demonstrate that when a sample contains live bacteria (E. coli) the whole reflectivity curve including the SPR region is clearly affected, and to adjust a theoretical model to the experimental curves, it is necessary to assume a complex refractive index of the nanofilm appreciably different than that of gold. The optical curve of the sensor provides more information than a conventional SPR measurements offering a more complete strategy for the analysis of biochemical substances and bacterial cell suspensions.

Direct observation of keyhole with an innovative layer-by-layer imaging method during deep penetration laser welding

In order to solve the difficult problem of observing the keyhole in deep penetration laser welding of metal materials, an innovative keyhole direct observation method based on layer-by-layer imaging technology is first proposed in this paper. In this novel method, a specially-designed composite workpiece consisting of an upper metal wedge and a lower glass trapezoidal prism is used. During deep penetration laser welding, a keyhole will form in and penetrate the metal wedge, whose cross section image that appears on the inclined bottom surface of the wedge is directly observed by a high speed video camera through the transparent glass prism. Then, the deep penetration laser welding is carried out with a fiber laser unit, by using the above proposed keyhole direct observation method, the keyhole cross section images at different depths are captured by the high speed camera. Finally, the images of the keyhole cross sections are processed and the outlines of the keyhole cross sections are extracted, from which the variation of the keyhole cross section during deep penetration laser welding of metal material is discussed. The result shows that from the top to the bottom, on one hand, the size of the keyhole cross section decreases gradually in general, but fluctuates to some extent, which indicates that the laser beam energy may not be uniformly absorbed into the keyhole along the depth and the evaporation site may change its position depending on the energy equilibrium there, on the other hand, the position of the keyhole cross section moves backward in the opposite direction of the welding velocity, whose motion tend agrees with the bending keyhole in the real case of laser welding.

Attenuated Total Reflection Far-Ultraviolet (ATR-FUV) Spectroscopy is a Sensitive Tool for Investigation of Protein Adsorption.

Attenuated total reflection far-ultraviolet (ATR-FUV) spectra in the 145-250nm region were studied for four kinds of proteins (two α-helix-rich proteins: bovine serum albumin (BSA) and lysozyme and two β-sheet rich proteins: concanavalin A and γ-globulin) in different solutions (pure water and phosphate buffered saline, or PBS) with different concentrations. All the spectra show a band at 191nm due to the π-π* transition of amide bonds of the proteins. The wavelength of the band does not change with their second structures, suggesting that the corresponding electronic transition mode is localized and polarized in the direction that is not affected by the difference in the peptide folding. The intensity of the 191nm band differs with the concentration of salt in the solution, suggesting that the band intensity reflects the adsorption density of a protein on the internal reflection element (IRE) made of a sapphire glass prism. According to the intensity changes of the band at 191nm, it is revealed that the properties in adsorption are different from one protein to another. It is assumed that there are two types of forces on the protein adsorption: one is that among the molecules and the other is that between a molecule and a substrate. The origin of force includes localized electrostatic polarity and affinity to water. The ions in the solvent give a marked effect on these forces, resulting in the difference in the response to adsorption density against the salt concentration in the solvent.

Simulation of surface plasmon resonance (SPR) layers of gold with silicon nitride as a Bi-layer biosensor

Surface Plasmon Resonance (SPR) has gotten a lot of attention in biomedical sensing. Many applications in medical diagnostics and single molecule detection have sparked interest in bio-sensing techniques. Surface Plasmon resonance (SPR) is an important phenomenon used for building sensors especially in the Biological fields. Simulation analysis (in Mat lab) has been made for SPR for gold (Au) layer with thickness (40 nm) and layer of silicon nitride (Si3N4) with different thickness (10- 70 nm) step 10, deposited on glass prism type N-LASF9_ glass with the sensitive layer was water at refractive index (∆n = 0, 0.01, 0.05 and 0.1). The analysis was taken for different wavelengths from UltraViolet wavelength 100 nm to Near Infra- Red wavelength 1000 nm. The properties of the surface Plasmon resonance angle (θSPR) have been calculated from plotted reflectance against incident angle θincid shows sharper resonance dip, narrower full width half maximum (FWHM), SPR dip length (Ld) increased so that improve in properties SPR and system. The SPR sensitivity (S) was calculated and recorded higher sensitivity about 134.

Study on the development and integration of 3D-printed optics in small-scale productions of single-use cultivation vessels.

Integrating optical sensors and 3D‐printed optics into single‐use (SU) cultivation vessels for customized, tailor‐made equipment could be a next big step in the bioreactor and screening platform development enabling online bioprocess monitoring. Many different parameters such as pH, oxygen, carbon dioxide and optical density (OD) can be monitored more easily using online measuring instruments compared to offline sampling. Space‐saving integrated sensors in combination with adapted optics such as prisms open up vastly new possibilities to precisely guide light through SU vessels. This study examines how optical prisms can be 3D‐printed with a 3D‐inkjet printer, modified and then evaluated in a custom made optical bench. The prisms are coated or bonded with thin cover glasses. For the examination of reflectance performance and conformity prisms are compared on the basis of measured characteristics of a conventional glass prism. In addition, the most efficient and reproducible prism geometry and modification technique is applied to a customized 3D‐printed cultivation vessel. The vessel is evaluated on a commercial sensor‐platform, a shake flask reader (SFR) vario, to investigate its sensing‐characteristics while monitoring scattered light with the turbidity standard formazine and a cell suspension of Saccharomyces cerevisiae as model organism. It is demonstrated that 3D‐printed prisms can be used in combination with commercial scattered light sensor‐platforms to determine OD of a microbial culture and that a 3D‐printed unibody design with integrated optics in a cultivation vessel is feasible. In the range of OD600 0–1.16 rel.AU a linear correlation between sensor amplitude and offline determined OD can be achieved. Thus, enabling for the first time a measurement of low cell densities with the SFR vario platform. Moreover, sensitivity is also at least three times higher compared to the commonly used method.

Optimization of hyperspectral systems of fluorescent testing of food products

Spectral analysis – based on the study of the emission spectra of various substances. Samples of the analyzed substance are “burned” under certain conditions, the substance evaporates and dissonates into atoms, which, when excited, give a spectrum. The light emitted in this case, passing through the glass prism of the spectroscope, is decomposed into its constituent parts (different light) and the experimenter observes a number of different lines (linear spectrum). The lines judge the presence of a particular element in the analyzed product.
 The higher the intensity of the lines, the higher the concentration of the substance. With the help of spectrographs, it is possible to photograph the radiation and, by the degree of blackening of the lines on the photographic plate, determine the concentration of a substance. The method is highly sensitive; impurities of substances determine up to 0.0001% – decimal fractions of a percent. The method is used to determine the mineral composition of products of plant and animal origin.
 Luminescence is the glow of atoms, ions, molecules, and more complex particles of matter, which occurs as a result of the transition of electrons in them upon returning from an excited state to a normal one. To transfer particles to an excited state, the definition of the amount of energy is summed up. Glow or part of the energy is released in the form of luminescence quanta. This method is used to determine vitamins, proteins, and fats in milk, to determine the freshness of meat and fish and various spoilage of vegetables, fruits, to detect preservatives, drugs, carcinogens, pesticides in food products.
 When assessing the quality of food products, great importance is given to their consistency. There are rheological methods for assessing consistency – the primary assessment of food products. Rheology studies the structural and mechanical properties of materials (deformation). Rheological properties include viscosity, elasticity, elasticity, and strength.
 Perhaps the emergence of new, more advanced methods that will become widespread, i.e., each consumer will have the opportunity to determine the quality of the product with the help of a mini device (such as a radioactive background meter, etc.) when buying.