• Title/Summary/Keyword: Nonlinear crystal

Search Result 123, Processing Time 0.024 seconds

QUANTUM CONTROL OF PARTICLES AT MATTER SURFACE OUTSIDE THE DOMAIN

  • Quan-Fang Wang
    • Nonlinear Functional Analysis and Applications
    • /
    • v.28 no.1
    • /
    • pp.11-36
    • /
    • 2023
  • In this presentation, the particles at the matter surface (metal, crystal, nano) will be considered as the control target outside the physical domain. As is well known that control problems of quantum particles at surface had been investigated in various aspects in last couple of years, but the realization of control would become rather difficult than theoretical results. Especially, whether surface control would be valid? what kind of particles at what kind of matter surfaces can be controlled? so many questions still left as the mystery in the current research literature and papers. It means that the direct control sometime does not easy. On the other hands, control outside the physical domain is quite a interest consideration in mathematics, physics and chemistry. The main plan is to take the quantum systems operator (such as Laplacian ∆) in the form of fractional operator (∆s , 0 < s < 1), then to consider the control outside of physical domain. Fortunately, there are many published articles in the field of applied mathematics can be referred for the achievement of control outside of domain. The external quantum control would be a fresh concept to do the physical control, first in the theoretic, second in the computational, final in the experimental issues.

Output power characteristics of a CW Nd:YVO4/KTP laser pumped by a tunable Ti:Sapphire laser (파장가변 티타늄 사파이어 레이저로 펌핑하는 연속발진 Nd:YVO4/KTP 레이저의 출력 특성)

  • 추한태;안범수;김규욱;이치원
    • Korean Journal of Optics and Photonics
    • /
    • v.13 no.2
    • /
    • pp.140-145
    • /
    • 2002
  • We measured the absorption rate of a Nd:YVO$_4$crystal with a thickness of 1 mm and the output power characteristics of a cw Nd:YVO$_4$/KTP laser with respect to the change of wavelength and the polarizations of a tunable Ti:sapphire pump laser with a linewidth of 0.2 nm. In the case of S-polarization (E┴$\pi$) and P-polarization (E∥$\pi$) of a pump laser, the maximum absorption rate of the crystal was 82% at 809.4 nm and 98% at 808.8 nm, and slope efficiencies for the output power of the Nd:YVO$_4$laser (1064 nm) were 43% and 52%, respectively. The maximum Nd:YYO$_4$laser output power of 516 mW was obtained from the P-polarization pump laser of 1000 mW. As a result of an intracavity frequency-doubling, slope efficiency for the output power of the Nd:YVO$_4$/KTP green laker (532nm) was 23% and the maximum output power of 205 mW with the beam quality (M$^2$) of 1.42 was obtained from the P-polarization pump laser of 1000 mW.

A neural-based predictive model of the compressive strength of waste LCD glass concrete

  • Kao, Chih-Han;Wang, Chien-Chih;Wang, Her-Yung
    • Computers and Concrete
    • /
    • v.19 no.5
    • /
    • pp.457-465
    • /
    • 2017
  • The Taiwanese liquid crystal display (LCD) industry has traditionally produced a huge amount of waste glass that is placed in landfills. Waste glass recycling can reduce the material costs of concrete and promote sustainable environmental protection activities. Concrete is always utilized as structural material; thus, the concrete compressive strength with a variety of mixtures must be studied using predictive models to achieve more precise results. To create an efficient waste LCD glass concrete (WLGC) design proportion, the related studies utilized a multivariable regression analysis to develop a compressive strength waste LCD glass concrete equation. The mix design proportion for waste LCD glass and the compressive strength relationship is complex and nonlinear. This results in a prediction weakness for the multivariable regression model during the initial growing phase of the compressive strength of waste LCD glass concrete. Thus, the R ratio for the predictive multivariable regression model is 0.96. Neural networks (NN) have a superior ability to handle nonlinear relationships between multiple variables by incorporating supervised learning. This study developed a multivariable prediction model for the determination of waste LCD glass concrete compressive strength by analyzing a series of laboratory test results and utilizing a neural network algorithm that was obtained in a related prior study. The current study also trained the prediction model for the compressive strength of waste LCD glass by calculating the effects of several types of factor combinations, such as the different number of input variables and the relevant filter for input variables. These types of factor combinations have been adjusted to enhance the predictive ability based on the training mechanism of the NN and the characteristics of waste LCD glass concrete. The selection priority of the input variable strategy is that evaluating relevance is better than adding dimensions for the NN prediction of the compressive strength of WLGC. The prediction ability of the model is examined using test results from the same data pool. The R ratio was determined to be approximately 0.996. Using the appropriate input variables from neural networks, the model validation results indicated that the model prediction attains greater accuracy than the multivariable regression model during the initial growing phase of compressive strength. Therefore, the neural-based predictive model for compressive strength promotes the application of waste LCD glass concrete.

Effect of Seed-layer on the Crystallization and Electric Properties of SBN60 Thin Films (SBN60 박막의 결정화 및 전기적 특성에 관한 씨앗층의 영향)

  • Jang, Jae-Hoon;Lee, Dong-Gun;Lee, Hee-Young;Jo, Sang-Hee
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
    • /
    • 2003.07b
    • /
    • pp.723-727
    • /
    • 2003
  • [ $Sr_xBa_{1-x}Nb_2O_6$ ] (SBN, $0.25{\leq}x{\leq}0.75$) ceramic is a ferroelectric material with tetragonal tungsten bronze (TTB) type structure, which has a high pyroelectric coefficient and a nonlinear electro-optic coefficient value. In spite of its advantages, SBN has not been investigated well compared to other ferroelectric materials with perovskite structure. In this study, SBN thin film was manufactured by ion beam sputtering technique using the prepared SBN target in $Ar/O_2$ atmosphere. SBN30 thin film of $1000{\AA}$ was pre-deposited as a seed layer on $Pt(100)/TiO_2/SiO_2/Si$ substrate followed by SBN60 deposition up to $3000{\AA}$ in thickness. As-deposited SBN60/SBN30 layer was heat-treated at different temperatures of 650, 700, 750, and $800^{\circ}C$ in air, respectively The crystallinity and orientation behavior as well as electric properties of SBN60/SBN30 multi-layer were examined. The deposited layer was uniform and the orientation was shown primarily along (001) plane from XRD pattern. There was no difference in the crystal structure with heat-treatment temperature, but the electric properties depended on the heating temperature and was the best at $750^{\circ}C$. In electric properties of Pt/SBN60/SBN30/Pt thin film capacitor prepared, the remnant polarization (2Pr) value was $15{\mu}C/cm^2$, the coercive field (Ec) 75 kV/cm, and the dielectric constant 1075, respectively.

  • PDF

The Real-Time Temporal and Spatial Diagnostics of Ultrashort High-Power Laser Pulses using an All-Reflective Single-Shot Autocorrelator

  • Kim, Ha-Na;Park, Seong Hee;Kim, Kyung Nam;Han, Byungheon;Shin, Jae Sung;Lee, Kitae;Cha, Yong-Ho;Jang, Kyu-Ha;Jeon, Min Yong;Miginsky, Sergei V.;Jeong, Young Uk;Vinokurov, Nikolay A.
    • Journal of the Optical Society of Korea
    • /
    • v.18 no.4
    • /
    • pp.382-387
    • /
    • 2014
  • An all-reflective, simple noncollinear second harmonic (SH) autocorrelator is described for monitoring the shot-to-shot behavior of ultrashort high-power laser pulses. Two mirrors are used for the dispersion-free splitting of a pulse into two halves. One of the mirrors is able to adjust the delay time and angle between two halves of the laser pulse in a nonlinear crystal. We present the possibility of real-time measurement of the pulse duration, peak intensity (or energy), and the pointing jitters of a laser pulse, by analyzing the spatial profile of the SH autocorrelation signal measured by a CCD camera. The measurement of the shot-to-shot variation of those parameters will be important for the detailed characterization of laser accelerated electrons or protons.

Effect of Seed-layer on the Crystallization and Electric Properties of SBN60 Thin Films (SBN60 박막의 결정화 및 전기적 특성에 관한 씨앗층의 영향)

  • Jang, Jae-Hoon;Lee, Dong-Gun;Lee, Hee-Young;Jo, Sang-Hee
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
    • /
    • 2003.08a
    • /
    • pp.85-88
    • /
    • 2003
  • $Sr_xBa_{1-x}Nb_2O_6$(SBN, $025{\leq}x{\leq}0.75$) ceramic is a ferroelectric material with tetragonal tungsten bronze (TTB) type structure, which has a high pyroelectric coefficient and a nonlinear electro-optic coefficient value. In spite of its advantages, SBN has not been investigated well compared to other ferroelectric materials with perovskite structure. In this study, SBN thin film was manufactured by ion beam sputtering technique using the prepared SBN target in Ar/$O_2$ atmosphere. SBN30 thin film of 500 ${\AA}$ was pre-deposited as a seed layer on Pt(l00)/$TiO_2$/$SiO_2$/Si substrate followed by SBN60 deposition up to 4500 ${\AA}$ in thickness. SBN60/SBN30 layer was deposited at different Oxygen amount of 0, 8.1, 17, and 31.8 sccm, respectively. The crystallinity and orientation behavior as well as electric properties of SBN60/SBN30 multi-layer were examined. The deposited layer was uniform and the orientation was shown primarily along (001) plane from XRD pattern. The crystal structure and the electric properties depended on the Oxygen amount, heating temperature and was the best at O2 = 8.1 seem, $750^{\circ}C$. In electric properties of Pt/SBN60/SBN30/Pt thin film capacitor prepared, the remnant polarization (2Pr) value was 13 ${\mu}C/cm^2$, the coercive field (Ec) 75 kV/cm, and the dielectric constant 1492, respectively.

  • PDF

Effect of Seed-layer thickness on the Crystallization and Electric Properties of SBN Thin Films. (SBN 박막의 결정화 및 전기적 특성에 관한 씨앗층 두께의 영향)

  • Jang, Jae-Hoon;Lee, Dong-Gun;Lee, Hee-Young;Cho, Sang-Hee
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
    • /
    • 2003.11a
    • /
    • pp.271-274
    • /
    • 2003
  • [ $Sr_xBa_{1-x}Nb_2O_6$ ] (SBN, $0.25{\leq}x{\leq}0.75$) ceramic is a ferroelectric material with tetragonal tungsten bronze (TTB) type structure, which has a high pyroelectric coefficient and a nonlinear electro-optic coefficient value. In spite of its advantages, SBN has not been investigated well compared to other ferroelectric materials with perovskite structure. In this study, SBN thin film was manufactured by ion beam sputtering technique using the prepared SBN target in $Ar/O_2$ atmosphere. SBN30 thin films of different thickness were pre-deposited as a seed layer on $Pt(100)/TiO_2/SiO_2/Si$ substrate followed by SBN60 deposition up to $4500\;{\AA}$ in thickness. As-deposited SBN60/SBN30 layer was heat-treated at different temperatures of 650, 700, 750, and $800\;^{\circ}C$ in air, respectively, The crystallinity and orientation behavior as well as electric properties of SBN60/SBN30 multi-layer were examined. The deposited layer was uniform and the orientation was shown primarily along (001) plane from XRD pattern. There was difference in the crystal structure with heat-treatment temperature, and the electric properties depended on the heating temperature and the seed-layer thickness. In electric properties of Pt/SBN60/SBN30/Pt thin film capacitor prepared, the remnant polarization (2Pr) value was $15\;{\mu}C/cm^2$, the coercive field (Ec) 65 kV/cm, and the dielectric constant 1492, respectively.

  • PDF

Defect-related yellowish emission of un doped ZnO/p-GaN:Mg heterojunction light emitting diode

  • Han, W.S.;Kim, Y.Y.;Ahn, C.H.;Cho, H.K.;Kim, H.S.;Lee, J.H.
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
    • /
    • 2009.06a
    • /
    • pp.327-327
    • /
    • 2009
  • ZnO with a large band gap (~3.37 eV) and exciton binding energy (~60 meV), is suitable for optoelectronic applications such as ultraviolet (UV) light emitting diodes (LEDs) and detectors. However, the ZnO-based p-n homojunction is not readily available because it is difficult to fabricate reproducible p-type ZnO with high hall concentration and mobility. In order to solve this problem, there have been numerous attempts to develop p-n heterojunction LEDs with ZnO as the n-type layer. The n-ZnO/p-GaN heterostructure is a good candidate for ZnO-based heterojunction LEDs because of their similar physical properties and the reproducible availability of p-type GaN. Especially, the reduced lattice mismatch (~1.8 %) and similar crystal structure result in the advantage of acquiring high performance LED devices. In particular, a number of ZnO films show UV band-edge emission with visible deep-level emission, which is originated from point defects such as oxygen vacancy, oxygen interstitial, zinc interstitial[1]. Thus, defect-related peak positions can be controlled by variation of growth or annealing conditions. In this work, the undoped ZnO film was grown on the p-GaN:Mg film using RF magnetron sputtering method. The undoped ZnO/p-GaN:Mg heterojunctions were annealed in a horizontal tube furnace. The annealing process was performed at $800^{\circ}C$ during 30 to 90 min in air ambient to observe the variation of the defect states in the ZnO film. Photoluminescence measurements were performed in order to confirm the deep-level position of the ZnO film. As a result, the deep-level emission showed orange-red color in the as-deposited film, while the defect-related peak positions of annealed films were shifted to greenish side as increasing annealing time. Furthermore, the electrical resistivity of the ZnO film was decreased after annealing process. The I-V characteristic of the LEDs showed nonlinear and rectifying behavior. The room-temperature electroluminescence (EL) was observed under forward bias. The EL showed a weak white and strong yellowish emission colors (~575 nm) in the undoped ZnO/p-GaN:Mg heterojunctions before and after annealing process, respectively.

  • PDF

The Growth of $MgO:LiNbO_3$ Single Crystal by Czochralski Method and its Density Measurement (Czochralski법에 의한 $MgO:LiNbO_3$단결정 성장과 밀도 측정)

  • Kim, Il-Won;Park, Bong-Chan;Kim, Gap-Jin
    • Korean Journal of Crystallography
    • /
    • v.4 no.2
    • /
    • pp.74-85
    • /
    • 1993
  • Single crystals of LiNbO3 have found extensive application in electro-optic and nonlinear optic devices. However, laser-induced refartive index inhomogeneities, which have been labeled opical damage impose limits on device optical damage in LiNbO3 is imporved if more than 4.5 rml% MgO is added to the melt The laser damage thrueshold increased as much as 100 times better then that of undoped crystals. The MgO doped cystal has thus been urterlsiv81y studied since then. In the study, Mgo:LiNbOs(MLA) single crystals dopsd with 0, 2.5, 5.0, 7.5, 10.0 mol% MgO have been grown by the czocrualski technique. The metls were prepared in the platinum crluible and 15∼20mm diameter crystals were grown with a length of 20∼30mm in a resitance heater. The growth rate was 2.5mm/hr, the rotation speed 15rpn. Before sawing MLN single crystals were annealed for 24 hours under atmosphere at a temperature of 1080℃. After sawing, we have found an annual ring cross section of MNA crystals only in the direction of perpendicilar to the c-axis. Nonuniform dispusion of MgO was pointed out that the cuties of the state of oxide were strongly affected by oxygen partial pressure in.

  • PDF

Absorption Spectra of Standard Gases for Wavelength Reference in C-band using a Supercontinuum Source Based on a Mode-locked Cr4+:YAG Laser (모드 잠금 Cr4+:YAG 레이저로부터 발생된 초 광대역 광원을 이용한 광통신 파장 영역의 표준 가스의 흡수스펙트럼)

  • Lee, Jong-Min;Jeon, Min-Yong;Ryu, Han-Young;Suh, Ho-Suhng
    • Korean Journal of Optics and Photonics
    • /
    • v.19 no.1
    • /
    • pp.54-59
    • /
    • 2008
  • We report on the measurements of absorption spectra from acetylene ($^{12}C_2H_2$) and hydrogen cyanide ($H^{13}C^{14}N$) for wavelength reference in the C-band (conventional band) region using a supercontinuum optical source generated from a mode-locked $Cr^{4+}$:YAG laser. The center wavelength of the mode-locked $Cr^{4+}$:YAG laser was 1510 nm and the pulse duration was 75 fs at 100 MHz repetition rate. The supercontinuum source achieved a flatness of ${\pm}5dB$ over a wavelength range of more than 400 nm, using a 20 m long photonic crystal fiber. The measured absorption spectra from acetylene ($^{12}C_2H_2$) and hydrogen cyanide ($H^{13}C^{14}N$) had more than 50 lines and were analyzed for wavelength standardization.