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Size and Morphology Investigation of PZT Nanofibers for Energy Harvesting Applications using Digital Holography
(2025-01-01)
Plaipichit, S.
;
Wicharn, S.
;
Puttharugsa, C.
;
Bintachitt, P.
;
Aeimbhu, A.
Polyvinylidene fluoride fibers composed of piezoelectric lead zirconate titanate under different fabrication conditions were investigated using digital holography technique. Larger PZT content and larger feed rates results in larger diameters, and thicker fibers respectively.
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Size and Morphology Investigation of PZT Nanofibers for Energy Harvesting Applications using Digital Holography
(2025-01-01)
Plaipichit, S.
;
Wicharn, S.
;
Puttharugsa, C.
;
Bintachitt, P.
;
Aeimbhu, A.
Polyvinylidene fluoride fibers composed of piezoelectric lead zirconate titanate under different fabrication conditions were investigated using digital holography technique. Larger PZT content and larger feed rates results in larger diameters, and thicker fibers respectively.
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Backscattering and transmission Raman spectroscopy systems in the quantitative analysis concentration of acetone solutions
(2023-01-01)
Charoenrit, T. P.
;
Wicharn, S.
;
Puttharugsa, C.
;
Limnonthatul, P.
;
Sassuvun, W.
Raman spectroscopy is a set of techniques based on Raman scattering properties, widely applied to analyze the composition of various substances. The techniques consist of 1) backscattering, which collects Raman signals scattered from the surface of a sample; and 2) transmission, which collects Raman signals transmitted by the surface of a sample in the opposite direction of a light source (which triggers less fluorescence than backscattering). In this paper, we will measure the Raman spectrum of acetone solution by the transmission Raman spectroscopy and the backscattering Raman spectroscopy systems that we set up. Those accessories we use are a 532-nanometer diode laser with 100 milliwatt power as the light source, a focusing lens, an objective lens used for amplifying the Raman signals scattered from the sample, and a long-pass filter used to block light with a wavelength shorter than 532 nanometers. For the experimental samples, there are acetone solutions each prepared at 1M, 3M, 5M, 7M, 9M, 11M, and 13M. In the results of this experiment, we found that the intensity of Raman peaks for each Raman shift of acetone and the molar concentrations of acetone measured by both systems have a linear function in the backscattering Raman system and have a quadratic function in the transmissions Raman system because in backscattering system have noise by fluorescence effect more than in transmission system and it might be the effect of the Beer-Lambert law.
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A circuit design of laser pulse generator
(2021-01-28)
Putchana, W.
;
Ratanavis, A.
;
Buranasiri, P.
In this research, a circuit design for square pulse generation was proposed by using microcontroller to generate pulse width modulation signal (PWM). The PWM signal, then, has generated the voltage for a laser diode of wavelength 650 nm. The frequency can be tuned approaching 0-5 MHz with the simplicity of the pulse width adjustment. The signals at the width of 130 x 10-9 s, 400 x 10-9 s, 600 x 10-9 s, 850 x 10-9 s, 1000 x 10-9s was examined to generate laser pulses. The heat in the pulse generator can be effectively controlled.
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Recursive transfer-matrix method for second-harmonic generation in a one-dimensional nonlinear photonic crystal at arbitrary incidence angle
(2021-01-28)
Threetanya, P.
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Puttharaksa, C.
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Plaipichit, S.
;
Buranasiri, P.
;
Wicharn, S.
In this paper, we derive a recursive transfer-matrix method (RTMM) and use the method to analyse the problem of second-harmonic generation (SHG) in a one-dimensional nonlinear photonic crystal (1D-NPC) under oblique incidence of fundamental-frequency (FF) wave and nondepleted pump approximation. This method is very simple and useful for determining SHG conversion efficiency at various incident angles of FF wave and thicknesses of nonlinear layer. The RTMM calculation results show that a maximum SHG conversion efficiency can be produced by the strong local FF field confinement in 1D-NPC due to optimal incidence angle and nonlinear layer thickness.
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Sample and system parameter estimation from local speckle pattern by fully numerically trained deep convolution neural network
(2021-01-01)
Seesan, T.
;
Oida, D.
;
Oikawa, K.
;
Buranasiri, P.
;
Yasuno, Y.
Deep convolutional neural network (CNN) based estimators for optical coherence tomography (OCT) are presented. The CNN analyze local OCT speckle patterns and estimate the sample's scatterer density and OCT resolutions. This estimator is intensity invariant, i.e., it does not use the net signal strength of OCT even to estimate the scatterer density. The CNN is trained by a huge training dataset that was generated by a simple simulator of OCT imaging. And hence, the CNN is trained without experimental datasets. The performance of CNN was evaluated by numerically generated OCT images, and good accuracies of the estimation were shown.
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Observations of the initial stages on reactive gas-timing sputtered TaO thin films by dynamic in situ spectroscopic ellipsometery
(2019-06-01)
Chittinan, D.
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Buranasiri, P.
;
Lertvanithphol, T.
;
Eiamchai, P.
;
Patthanasettakul, V.
Dynamic in-situ spectroscopic ellipsometry (iSE) was employed to investigate the growth mechanism of the tantalum oxide (TaO) film on silicon wafer substrate deposited by reactive gas-timing RF magnetron sputtering compared with conventional reactive sputtering. The effect of reactive gas timing parameter on physical structure and optical property were analyzed by both the continuous and island film growth model with Tauc-Lorentz optical model. The variation of refractive index, film thickness and void volume fraction were obtained from dynamic fits of iSE data indicated that the growth process of the amorphous TaO thin films was divided into two regimes: the nucleation stage and continuous-layer stage. These stages were observed during deposition although the initial film growth stage corresponds to the island film growth model. The study demonstrates that sputtered TaO by the RGT technique at the O<inf>2</inf> on-off gas timing has played a crucial factor in improving the formation of nucleation stage and that the deposited TaO thin films were high deposition rate with high refractive index. The complementary field emission scanning electron microscope (FE-SEM) and transmission electron microscope (TEM) showed a good agreement with the film thickness and morphology obtained from dynamic iSE measurement. The real-time monitoring of iSE offers important evidences to understand the growth mechanism of reactive gas-timing technique.
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Polarization effect of quantitative phase imaging using digital holography method
(2019-01-01)
Gasosoth, T.
;
Jongjinakool, K.
;
Buranasiri, P.
In this study, we investigate polarization effect of quantitative phase imaging (QPI) using digital holography (DH) technique. By using different polarization state of writing beam the reconstructed images of different kinds of samples including biological cells from DH interferometer have been analyzed and shown their difference of quantitative measurement with reconstructed images of unpolarized writing fields. In addition, the property changes of some samples have been studied using the property analysis of the polarization image fields.
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Virtual X-Ray Diffractometer using Acoustic Wave for Material Science Education
(2018-12-19)
Plaipichit, S.
;
Wicharn, S.
;
Puttharugsa, C.
;
Wanakamol, P.
;
Buranasiri, P.
In this research, virtual X-Ray Diffractometer (XRD) using acoustic wave for material science education has been proposed. Acoustic wave with frequency in ultrasonic range has been used to characterize acoustic crystal structures. The dimensions of model structure, which are in order of ultrasonic wavelength region, have been formed by three dimensional printer (3D printer) and cotton swab. The angle of ultrasonic source and detector have been swept to record reflected wave signal of each angle. The peak of each angle have been selected to calculate lattice spacing by Bragg's law and then compared with the implemented structure. The results show signal peaks of each diffracted angle. The experimental results showed that the lattice spacing values obtained from acoustic experiment were in good agreement with the measured values of the implemented structure. This virtual XRD system provide to be an efficient tool for understanding about crystal structure characterization.
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Backward Third-Harmonic Pulse Generation in a One-Dimensional PIM/NIM Structure
(2018-12-19)
Buranasiri, P.
;
Wicharn, S.
;
Yindeesuk, W.
In this work, a set of couple-mode equations for describing a backward third harmonic generation (BTHG) in a one-dimensional periodic structure of positive-index material (PIM) layers and third-order nonlinear negative-index material (NIM) layers was analysed using multiple-scale method. Due to the negative-index phase matching and band-edge field enhancement the intensities of backward third-harmonic pulsed generated from the PIM/NIM periodic structure is increased for 100 time of those generated from a single NIM medium.

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