Buranasiri, Prathan

Preferred name

Buranasiri, Prathan

Alternative Name

Buranasiri, P.

Main Affiliation

School of Science

prathan.bu@kmitl.ac.th

Now showing 1 - 10 of 57

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NiO thickness measurement using a rectangular-type Sagnac interferometer as the material transport layer in a perovskite solar cell
(2024-04-10)
Usman, Abdullahi
;
Bhatranand, Apichai
;
Jiraraksopakun, Yuttapong
;
Muhammad, Khalid Sabo
;
Buranasiri, Prathan
This work aims to utilize a phase-shifting technique in a rectangular-type Sagnac interferometer (RTSI) to measure the thickness of a thin film of nickel (II) oxide (NiO) in an electron transport layer (ETL) in perovskite solar cell preparation. TheNiO layer is deposited on a fluorine-doped tin oxide (FTO) glass substrate. In the RTSI setup, the signal output from the interferometer is divided into the reference and testing arms using a nonpolarizing beam splitter (NPBS). The balanced photodetectors then detect the signal, with the FTO/NiO layer placed in the testing armand pure FTOin the reference arm. By analyzing the signal intensities at polarization settings of 0° to 180°, the phase shift and thickness of theNiO layer can be determined. The thickness values of FTOandNiO films obtained through three different phase-shifting algorithms of three-, four-, and five-steps are calculated. The obtained NiO thickness values are validated against scanning electron microscopy (SEM). Finally, by considering the NiO thickness value that exhibits the lowest percentage error compared to one from SEM, it is confirmed that the three-step algorithm is the most suitable scheme for obtaining intensities at 0°, 45°, and 90°. Therefore, the proposed setup shows promise as a replacement forSEMin thickness measurements.
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Phase-matched second-harmonic generation in core-shell nanowire hyperbolic metamaterial
(2022-09-01)
Wicharn, Surawut
;
Banerjee, Partha P.
;
Buranasiri, Prathan
Second-harmonic generation is well-known nonlinear frequency conversion technique, which can be applied in nonlinear optical characterization of materials and all-optical signal processing. This phenomenon requires phase-matching to maximize the conversion efficiency of generated second-harmonic field. But the phase-matching condition is difficult to achieve because of dispersion of naturally existing materials. To overcome this limitation, we propose an innovative phase-matching technique, which is called hyperbolic phase-matching, that can be possibly achieved by managing dispersion of a hyperbolic metamaterial. Here, the hyperbolic metamaterial is made of two-dimensional periodic arrays of core-shell nanowires, which have aluminium gallium arsenide as a core and gold as a shell, immersed in anodic aluminium oxide matrix. We have demonstrated phase-matched conditions for two different non-collinear second-harmonic interacting configurations in the metamaterial, which can be created by tuning incident angle of pump field to optimal values. Finally, conversion efficiencies of transmitted and reflected second-harmonic pulses as a function of incident angle and input pulse intensity were examined. The maximum conversion efficiencies are obtained at optimal incident angle and largest pumping intensity.
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Recursive-formula for second-harmonic generation problem in photonic hypercrystal
(2022-09-01)
Buranasiri, Prathan
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Plaipichit, Suwan
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Puttharugsa, Chokchai
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Wicharn, Surawut
In this work, we proposed a recursive-formula based on transfer-matrix method to solve problem of second-harmonic generation by obliquely incident fundamental-harmonic wave in a photonic hypercrystal, which is composed of one-dimensional periodically alternating arrangement of nonlinear hyperbolic metamaterial layer with anisotropic permittivities: ε<inf>axx</inf>, ε<inf>azz</inf> and layer thickness: a and linear dielectric layer with isotropic permittivity: ε<inf>a</inf> and layer thickness: b. This proposed formula was very simple and accurate for calculating conversion efficiency of second-harmonic generation at various incident angles of fundamental-harmonic wave and thicknesses of nonlinear hyperbolic metamaterial layer. The numerical results showed that the maximum conversion efficiency can be achieved by the strong local field confinement of fundamental-harmonic wave in the photonic hypercrystal and phase-matching due to optimal values of hypercrystal layer thickness and incident angle of fundamental-harmonic wave.
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Asymmetrical resonant cavity thin film devices designed for vanadium dioxide applications
(2025-01-01)
Padungatthakij, Chettanat
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Wicharn, Surawut
;
Buranasiri, Prathan
Vanadium dioxide (VO2) is a volatile phase change material (PCM) that undergoes a rapid structure transition when heated above and reverts when cooled below its transition temperature. This transition alters its optical properties significantly when compared to normal materials, making it possible to design a thin film device with switching operation mode. In this paper, we redesign VO2-based devices with two different use cases to introduce an asymmetrical resonant cavity (AsymReca) structure. The redesigned process aimed to enhance the optical performance of the central VO2 layer and gave it an antireflection property. Using simulation, we discuss the advantages and limitations of this design approach and highlighting its potential use case.
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Phase-change metamaterial for tunable polarization conversions in terahertz region
(2024-01-01)
Wicharn, Surawut
;
Buranasiri, Prathan
In this study, a phase-change metamaterial (PCM) is proposed to be applied as tunable terahertz (THz) polarization converter. The structure of PCM consists of 4 layers such as hyperbolic medium (HM) layer, vanadium dioxide (VO2) layer, the polyimide (PI) layer, and gold (Au) gratings, respectively. The HM layer is made by two-dimensional arrangement of gold (Au) nanowires in x-y plane immerged in PI host slab. The polarization converting characteristics of PCM structure is investigated numerically by using anisotropic transfer-matrix method (ATMM). The numerical results show that, when the VO2 is in insulating state, the PCM structure provides transmitted cross-linear polarization conversion and when the VO2 is changed to conducting state, the PCM structure gives both reflective cross-linear polarization and linear-to-circular polarization conversions.
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Phase-shifting determination and pattern recognition using a modified Sagnac interferometer with multiple reflections
(2024-02-01)
Usman, Abdullahi
;
Bhatranand, Apichai
;
Jiraraksopakun, Yuttapong
;
Muhammad, Khalid Sabo
;
Buranasiri, Prathan
This work has implemented a diverse modification of the Sagnac interferometer to accommodate various measurement requirements, including phase shifting, pattern recognition, and a morphological analysis. These modifications were introduced to validate the adaptability and versatility of the system. To enable phase shifting using the multiple light reflection technique, a half-wave plate (HWP) was utilized with rotations at 0, π/8, π/4, and 3π/8 radians, generating four interference patterns. It is possible to observe a distinct circular fringe width as the polarized light experiences diffraction at the interferometer’s output as it travels through a circular aperture with various diameters ranging from 0.4 to 1 mm. Further modifications were made to the setup by inserting a pure glass and a fluoride-doped tin oxide (FTO) transparent substrate into the common path. This modification aimed to detect and analyze a horizontal fringe pattern. Subsequently, the FTO substrate was replaced with a bee leg to facilitate morphology recognition. A deep learning-based image processing technique was employed to analyze the bee leg morphology. The experimental results showed that the proposed scheme succeeded in achieving the phase shift, measuring hole diameters with errors smaller than 1.6%, separating distinct transparent crystals, and acquiring the morphological view of a bee’s leg. The method also has successfully achieved an accurate surface area and background segmentation with an accuracy over 87%. Overall, the outcomes demonstrated the potential of proposed interferometers for various applications, and the advantages of the optical sensors were highlighted, particularly in microscopic applications. © 2024 Optica Publishing Group
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Photorefractive Effect in an Imperfect Cerium Doped Barium Titanate Crystal: Reflection Grating Case
(2026-01-01)
Khotphuthon, Wasuphon
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Plaipichit, Suwan
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Suchat, Suebtarkul
;
Buranasiri, Prathan
The photorefractive (PR) effect, a nonlinear optic phenomenon, occurs in materials that have electro-optic (EO) properties. When two coherent beams of light interfere with each other in a PR material, donor electrons between valence band and conduction band, caused by material impurity, absorb the photon and are excited into the conduction band and generate electron-hole pairs. This process induces a periodic electric field called a space charge field that alters the material’s refractive index due to the EO effect. In this research, we explored reflection grating (RG) in an imperfect Ce-doped BaTiO3 crystal and then showed optical image correlation using the RG. Two beam coupling was investigated using two non-Gaussian incident beams on the opposite surface of an imperfect Ce-doped BaTiO3 crystal. Light at green wavelengths from a semiconductor laser was used as the source of the incident beams and entered at certain angles relative to the crystal c-axis. Large beam coupling power was observed in both incident directions when the angle between both incident beams is at Bragg’s angle in the direction of the c-axis. The diffraction light was found to be in the same polarization as the incident beam. In addition, interesting results for the optical correlation using reflection grating were demonstrated. These results suggest that by doping BaTiO3 with cerium, strong beam coupling or photorefractive grating can be observed with certain incident writing angles on the crystal, which could be utilized in future flexible holographic devices in the future.
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Effect of the carbon dioxide concentration on the Refractive Index of air in a long gauge block interferometer
(2020-07-03)
Kohmun, Kanokporn
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Limsuwan, Pichet
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Ranusawud, Monludee
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Buranasiri, Prathan
In our previous work, four environment parameters including temperature, pressure, relative humidity and carbon dioxide concentration in a long gauge block interferometer chamber were measured continuously for 24 h. The refractive index of air in the chamber depending on three measured parameters was determined using the updated Edlén equation by assuming that CO<inf>2</inf> concentration is constant at 450 ppm. In this study, the carbon dioxide concentration term was added into the updated Edlén equation and four environment parameters including temperature, pressure, relative humidity and CO<inf>2</inf> concentration were measured continuously for 12 h. To characterize the influence of the carbon dioxide concentration on the refractive index of air in a long gauge block interferometer chamber, the refractive index of the chamber contents was determined using updated Edlén equations with constant and with variable carbon dioxide concentration terms. The results showed that the refractive index values obtained from the updated Edlén equations with constant and variable CO<inf>2</inf> concentration terms were equal to 1.000268244 and 1.000268261, respectively.
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Design and simulation of asymmetric Y-junction beam splitter with controllable splitting based on adjusted air-hole defect
(2022-01-01)
Phongwisit, Phachara
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Kamoldilok, Surachart
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Buranasiri, Prathan
;
Srinuanjan, Keerayoot
;
Limsuwan, Pichet
We report a construction of a new asymmetric Y-junction beam splitter with a controllable splitting ratio and simulate this splitter. The splitter is based on InP, has the area 65.0 µm<sup>2</sup> and operates at the light wavelengths 1.48 and 1.55 µm. Under condition of no air-hole defect, the splitting ratio for the output ports 1 and 2 is equal to 92/8 at the both wavelengths. To control the splitting ratio, air-hole defects with different (diamond, square and cylinder) shapes are introduced at the junction between the two output ports. Our simulations confirm that the splitting ratio of the beam splitter can be efficiently controlled by changing the size and the shape of the air-hole defect. The maximal splitting ratios at our operating wavelengths are equal to 10/90 and 14/86 and the appropriate average insertion losses amount to 0.36 and 0.31 dB for all of defect shapes.
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Optimizing indoor digital holography for photovoltaic surface analysis: A novel approach for solar PV testing conditions
(2025-01-01)
Bako, Abdullahi
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Voochaiphum, Bunyarit
;
Suchat, Suebtarkul
;
Buranasiri, Prathan
The sun is a clean, inexhaustible, free energy source, and it is environmentally safe. The rapid expansion of the solar photovoltaic (PV) industry demands innovative quality control techniques for defect detection and efficiency optimization of solar cells. Traditional methods such as electroluminescence, photoluminescence, and infrared thermography have limitations in detection resolution, real-time monitoring, and surface characterization. In this research, a novel approach digital holography-based non-contact method for detecting and analyzing defects in solar cells, such as micro-structural defects, surface roughness, dust, scratch, and cracks, was investigated. Laser module was used as our light source to optimize indoor test conditions. An integrated recognition system was developed to automate and improve accuracy using real hologram images. Reconstruction images and Fourier transforms were used to extract the phase and amplitude across the solar PV cell. This preserved the module's integrity and providing detailed defect information from the solar surface.

Buranasiri, Prathan

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