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Ultra-broadband phase-matching ultrashort-laser-pulse measurement techniquesLee, Dongjoo 03 July 2007 (has links)
In the past several decades the technology for the creation and use of ultrashort pulses has progressed tremendously. Now, it is possible to generate laser pulses as short as a few femtoseconds in duration, and such pulses have been used for a wide range of applications. In addition, the means of measuring these pulses has progressed so rapidly. However, despite recent great advances in ultrashort-pulse measurement techniques, much remains to be done. In particular, pulse-measurement devices have relatively small wavelength-tuning ranges, and the phase-match is problematic for the pulses with a wide bandwidth such as supercontinuum. In this thesis, I will demonstrate a new pulse measurement technique which can phase-match ultra-broad bandwidth of super-continuum using transient grating frequency-resolved-optical-gating (TG FROG). Also, I will demonstrate a simplified device which can measure the UV ultra-short pulse using transient grating process, one of the third-order nonlinearity and can cover from UV to IR with the same arrangement.
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A Thermal Switch from Thermoresponsive Polymer Aqueous SolutionsMa, Yunwei 29 November 2018 (has links)
Thermal switch is very important in today’s world and it has varies of applications including heat dissipation and engine efficiency improving. The commercial thermal switch based on mechanical design is very slow and the structure is too complicated to make them smaller. To enable fast thermal switch as well as to make thermal switch more compact, I try to use second-order phase transition material to enable our thermal switch. Noticing the transition properties of thermoresponsive polymer for drug delivery, its potential in thermal switch can be expected. I used Poly(N-isopropylacrylamide) (PNIPAM) as an example to show the abrupt thermal conductivity change of thermoresponsive polymer solutions below and above their phase transition temperature. A novel technique, transition grating method, is used to measure the thermal conductivity. The ratio of thermal switch up to 1.15 in transparent PNIPAM solutions after the transition is observed. This work will demonstrate the new design of using second-order phase transition material to enable fast and efficient thermal switch. / Master of Science / Controllable thermal conductivity (thermal switching) is very important to thermal management area and useful in a wide area of applications. Nowadays, mechanical thermal conductivity controller device suffers from large scale and slow transition speeds. To solve these problems, I tired the phase transition thermoresponsive polymers to create quick thermal switching because the thermal conductivity will change with the phase. Thermoresponsive polymers show sharp phase changes upon small changes in temperature. Such polymers are already widely used in biomedical-like applications, the thermal switch applications are not well-studied. In this work, I tested Poly(N-isopropylacrylamide) (the abbreviation is PNIPAM) as an example to show the quick thermal conductivity changing ability of thermoresponsive polymer when the transition was happened .I used a novel approach, called the TTG, transient thermal grating. It has easy setup and high sensitivity. The thermal conductivity switching ratio as high as 1.15 in transparent PNIPAM solutions after transition is observed. This work will give new opportunities to control thermal switches using the phase change of thermoresponsive material or abrupt other phase change material in general.
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Measurement of Material Q in Rayleigh Waves with a Laser Based Acoustic SpectrometerMassey, Eric William 21 November 2006 (has links)
This thesis describes a method developed to quickly measure the Rayleigh wave Q for a test material using a minimally invasive laser probe. The probe was donated to our lab by Dr. Alex Maznev at Phillips AMS in Natick, Ma. The machine was originally used to measure ultra thin film metal thicknesses; however we have utilized it to suit our needs. The optics head relies on a technique known as the transient grating method to generate a dispersion curve. This dispersion curve is then operated on by a local approximation for the Kramers-Kronig relations. The Kramers-Kronig relations for acoustic waves relate the real and imaginary parts of the dynamic compressibility to one another. The real part of the compressibility relates to the phase velocity of the wave and the imaginary part relates to the attenuation. Once the attenuation for the corresponding range of frequencies is determined the last step is to apply both the dispersion data and the attenuation data to the material Q equation to find Q over a range of frequencies. This thesis discusses the design of the machine, the theory behind the Kramers-Kronig relations and surface acoustic waves, the experimental procedure, and lastly results generated by the technique.
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The Study of Temperature Dependence of Pulse Laser-Induced Transient Grating Effect in Azo-Dye Doped Liquid CrystalsKuo, Ming-Shiun 07 July 2004 (has links)
Azo-Dye Doped Liquid Crystal (DDLC) is a developed material which can be used to fabricate optical shutter, displays, etc. In this thesis, we presents of the transient grating on a planar aligned DDLC.
The effect of various polarizations of writing and probing beams, and of temperature on the transient grating are examined. Then, we propose a model to explain the result. Through this study, we understand the factors that determine the light-induced aligning Dye effect on nematic liquid crystals.
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Photoreaction dynamics of Cyanobacterial phytochrome 1 (Cph1) / バクテリオフィトクロムCph1の光反応ダイナミクスの研究Takeda, Kimitoshi 25 March 2019 (has links)
京都大学 / 0048 / 新制・課程博士 / 博士(理学) / 甲第21595号 / 理博第4502号 / 新制||理||1646(附属図書館) / 京都大学大学院理学研究科化学専攻 / (主査)教授 寺嶋 正秀, 教授 林 重彦, 教授 竹腰 清乃理 / 学位規則第4条第1項該当 / Doctor of Science / Kyoto University / DGAM
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Studies on the reaction dynamics of structural and intermolecular interaction changes during signal transduction of the photosensor protein YtvA / 光センサータンパク質YtvAのシグナル伝達過程における構造および分子間相互作用変化の反応ダイナミクスに関する研究Choi, Suekwoo 23 March 2021 (has links)
京都大学 / 新制・課程博士 / 博士(理学) / 甲第23033号 / 理博第4710号 / 新制||理||1675(附属図書館) / 京都大学大学院理学研究科化学専攻 / (主査)教授 寺嶋 正秀, 教授 林 重彦, 教授 渡邊 一也 / 学位規則第4条第1項該当 / Doctor of Science / Kyoto University / DGAM
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Light-intensity dependent photoreaction and enzyme activity of BlrP1 / BlrP1の光強度に依存した光反応と酵素活性に関する研究Shibata, Kosei 23 March 2022 (has links)
京都大学 / 新制・課程博士 / 博士(理学) / 甲第23723号 / 理博第4813号 / 新制||理||1689(附属図書館) / 京都大学大学院理学研究科化学専攻 / (主査)教授 寺嶋 正秀, 教授 林 重彦, 教授 渡邊 一也 / 学位規則第4条第1項該当 / Doctor of Science / Kyoto University / DGAM
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Development of a novel method for time-resolved-diffusion detection of protein reactions and its application / 時間分解拡散観測手法を利用したタンパク質反応検出法の開発とその適用Takaramoto, Shunki 23 March 2021 (has links)
京都大学 / 新制・課程博士 / 博士(理学) / 甲第23031号 / 理博第4708号 / 新制||理||1675(附属図書館) / 京都大学大学院理学研究科化学専攻 / (主査)教授 寺嶋 正秀, 教授 林 重彦, 教授 渡邊 一也 / 学位規則第4条第1項該当 / Doctor of Science / Kyoto University / DGAM
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Studies on interaction between light sensor protein PYP and its downstream protein PBP / 光受容タンパク質PYPと下流タンパク質PBPの相互作用に関する研究Kim, Suhyang 23 March 2022 (has links)
京都大学 / 新制・課程博士 / 博士(理学) / 甲第23720号 / 理博第4810号 / 新制||理||1688(附属図書館) / 京都大学大学院理学研究科化学専攻 / (主査)教授 寺嶋 正秀, 教授 林 重彦, 教授 渡邊 一也 / 学位規則第4条第1項該当 / Doctor of Science / Kyoto University / DGAM
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Studies on the photo-induced conformational changes of blue light sensor BLUF proteins / 青色光センサーBLUFタンパク質の光誘起構造変化に関する研究Tokonami, Shunrou 25 March 2024 (has links)
京都大学 / 新制・課程博士 / 博士(理学) / 甲第25136号 / 理博第5043号 / 京都大学大学院理学研究科化学専攻 / (主査)教授 寺嶋 正秀, 教授 林 重彦, 教授 渡邊 一也 / 学位規則第4条第1項該当 / Doctor of Science / Kyoto University / DGAM
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