Arterial wall morphology depends strongly on the hemodynamic environment experienced in vivo. The mammalian heart pumps blood through rhythmic contractions forcing blood vessels to undergo cyclic, mechanical stimulation in the form of pulsatile blood pressure and flow. While it has been shown that stepwise, chronic increases in blood pressure and flow modify arterial wall thickness and diameter respectively, few studies on arterial remodeling have examined the influences that pulsatility (i.e., the range of cyclic stimuli) may have on biaxial wall morphology. We experimentally studied the biaxial behavior of carotid arteries from 8 control (CCA), 15 transgenic, and 21 mechanically altered mice using a custom designed mechanical testing device and correlated those results with hemodynamic measurements using pulsed Doppler. In this dissertation, we establish that increased pulsatile stimulation in the right carotid artery after banding (RCCA-B) has a strong affect on wall morphological parameters that peak at 2 weeks and include thickness (CCA=24.8±0.878, RCCA-B=99.0±8.43 μ m), inner diameter (CCA=530±7.36, RCCA-B=680±32.0μ m), and in vivo axial stretch (CCA=1.7±0.029, RCCAB= 1.19±0.067). These modifications entail stress and the change in stress across the cardiac cycle from an arterial wall macro-structural point of view (i.e., cellular and extracellular matrix) citing increases in collagen mass fraction (CCA=0.223±0.056, RCCA-B=0.314±0.011), collagen to elastin ratio (CCA=0.708±0.152, RCCA-B=1.487±0.26), and cross-sectional cellular nuclei counts (CCA=298±58.9, RCCA-B=578±28.3 cells) at 0, 7, 10, 14, and 42 post-banding surgery. Furthermore, we study the biomechanical properties of carotid arteries from a transgenic mouse of Marfan Syndrome. This arterial disease experiences increased pulse transmission and our findings indicate that alterations occur primarily in the axial direction. The above results are all applied to a predictive biaxial model of Cauchy stress vs. strain.

We simulate ultrashort pulse propagation through water by numerical methods, which is a kind of optical communication research. Ultrashort pulses have been known to have non Beer-Lambert behavior, whereas continuous waves (CW) obey the Beer-Lambert law. People have expected that the ultrashort pulse loses less intensity for a given distance in water than CW which implies that the pulse can travel over longer distances. In order to understand this characteristic of the pulse, we model numerically its spectral and temporal evolution as a function of traveling distance through water. We achieve the pulse intensity attenuation with traveling distance, obtain the temporal envelope of the pulse and compare them with experimental data. This research proves that the spectral and temporal profile of a pulse can be predicted knowing only the intensity spectrum of the input pulse and the refractive index spectrum of water in the linear regime. The real feasibility and the advantage of using an ultrashort pulse as a communication carrier will also be discussed.

Genetic algorithm is often used to find the global optimum in a multi-dimensional search problem. Inspired by the natural evolution process, this algorithm employs three reproduction strategies -- cloning, crossover and mutation -- combined with selection, to improve the population as the evolution progresses from generation to generation. Femtosecond laser pulse tailoring, with the use of a pulse shaper, has become an important technology which enables applications in femtochemistry, micromachining and surgery, nonlinear microscopy, and telecommunications. Since a particular pulse shape corresponds to a point in a highly-dimensional parameter space, genetic algorithm is a popular technique for optimal pulse shape control in femtosecond laser experiments. We use genetic algorithm to optimize third harmonic generation (THG), and investigate various pulse shaper options. We test our setup by running the experiment with varied initial conditions and study factors that affect convergence of the algorithm to the optimal pulse shape. Our next step is to use the same setup to control coherent anti-Stocks Raman scattering. The results show that the THG signal has been enhanced.

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.

Recently, lifetime imaging has become a subject of intensive research. Lifetime is an important parameter to understand the dynamics of targeted objects and its applications ranges from fluorescence decay of biological objects to relaxation of semiconductor materials and devices. Many methods, such as time-correlated single photon counting (TCSPC) and phase detection in frequency domain, were developed to measure the characteristic lifetime. These methods are now rather matured and widely applied in various studies. However, these methods are only effective for lifetime longer than 100 picoseconds due to the bandwidth limitation of high-speed electronics. For even faster temporal resolution, novel techniques that do not rely on high-speed electronics will be required. In this study, we are integrating an autocorrelator with a galvo-based laser scanning microscope to enable imaging with very high temporal resolution. The principle and technique of pump-probe is implemented through the autocorrelator. In this way, imaging based pump-probe measurements can be realized. Specifically, we have applied the experimental setup so developed in measuring fluorescent dyes and semiconductor devices.

With scarce the energy source and the worsened environment pollution, how to create and use a clean and never exhausted energy is becoming very important day by day. This thesis we proposed the research and development of a solar energy storage system with fuzzy logic control. This solar energy storage system is composed of the solar cell, charger, batteries, buck converter and digital a signal processor. The solar energy storage charging system charger is based on buck circuit control with battery cycle pulse charging. with the fuzzy control theory combined in the tactics of charging , it¡¦s can improve the efficiency of charging, suppress the abnormally battery temperature rise, lengthen the battery¡¦s life, and reduce the waste used. In the experiment, four different charging methods, with the same starting voltage, are compared in terms of temperature control. Among the four methods, the fuzzy logic control proposed in this thesis is able to control the battery temperature at a good 30 Celsius Degree. Experimental and simulation results demonstrate the effectiveness and validity of the system.

This thesis utilized pulse shaping technology to study chirp response of SSBR and attempt to analyze contribution of SSBR in mode-locked process. A home-made pulse shaping system (based on 4f scheme) with Freezing algorithm and Gerchberg-Saton algorithm was demonstrated. A normal dispersion at nonabsorbable wavelength and an anomalous dispersion around absorbable wavelength region in SSBR were obtained. Meanwhile, a Kramers-Kronig relation like behavior of pulse depression/broadening ratio in the strained multiple quantum well was observed and also refer to that pulse starting force is stronger at short wavelength. Decrease of pulse compression with increasing power of negative chirp incident pulse was characterized. Unclear power dependence for positive chirp case was also performed. These could be due to competition of band-filling and pump dump process. In addition, higher reflectivity and tendency of lower saturation fluence of SSBR for negative chirp incident pulse were observed.

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Nonlinear optical microscopy (NLOM) offers many advantages when imaging intact biological samples. By using ultrafast lasers in the near infrared and two photon excitation (TPE), signal production is limited to the focal volume and provides an excellent means for rendering thin, microscopic images from within the sample. Exogenous fluorophores/lumiphores may be used as efficient contrast agents to tag specific targets and provide enhanced signal. The efficiency of the TPE process in these contrast agents is broadly assumed to vary inversely with the laser pulsewidth, τ. In this work, we investigate the TPE efficiency of transform limited broadband (~133nm, ~10fs) and narrowband (~11nm, ~170fs) pulses in the generation of twophoton luminescence from semiconductor nanocrystals or quantum dots (QD's) both theoretically and experimentally. Compared to standard organic dyes, QD's possess a relatively broad, uniform spectral response that enables better use of the full bandwidth from the broadband laser. Theoretical calculations including both degenerate and non-degenerate TPE indicate a rolloff from the 1/τ behavior as the pulses' spectral bandwidth becomes broader than the absorption spectra of the QD's. Experimentally measured enhancement in luminescence intensity while using a broadband pulse is compared with the simulated enhancement in two-photon luminescence. A combination of increased understanding of the excitation processes in NLOM and proper selection of contrast agents will help in advancing the role of broadband ultrafast lasers in NLOM.

This thesis presents a low power consumption and low phase noise CMOS integer-N frequency synthesizer, and it bases on a charge-pump PLL topology. The frequency synthesizer can be used for IEEE 802.16b unlicensed band of WiMAX(World Interoperability for Microwave Access) from 5.725GHz to 5.825GHz. It provides the one ration frequency ranged from 5.13GHz to 5.22GHz for the local oscillator in RF front-end circuits. The proposed frequency synthesizer consists of a phase-frequency detector, a charge pump, a low-pass loop filter, a voltage-controlled oscillator, and a pulse-swallow divider. In system design, we present the new architecture for voltage-controlled oscillator to achieve low power consumption and low phase noise. Moreover divider is implemented by an optimal extended true single-phase clock-base prescaler. It can achieve high-resolution frequency operation and reduction of power consumption. This chip is fabricated in a TSMC 0.18£gm CMOS 1P6M technology process. The whole chip area is 1.1 mm2.