In this thesis, we have set up a SiO2 sputter system. The system includes sputter gun, RF power supply, RF power controller, turbo pump, quick access door, cooling water tubes, gas lines, electric circuits etc. We applied sputter techniques for quantum well intermixing (QWI) process. We can adjust the pressure, gas, RF power etc. of the sputter system to fit the best QWI conditions and then sputter a SiO2 film on the samples. The samples with multiple quantum wells were grown by our team members using molecular beam epitaxy system. After SiO2 film deposition, the samples were annealed by Rapid Thermal Process. The annealing temperatures are about 650¢J-750¢J. Following the thermal annealing, room-temperature PL measurements were used to study the blue shift and intensity change after QWI process. After our hard working, we had fixed many problems of sputter system. We have obtained useful data through many QWI experiments. Our results are listed as follows : PL intensity : We use RF power = 100W, sputter time = 5 min., annealing temperature = 675¢J, annealing time = 30 sec. PL intensity has been enhanced by 25 times. Blue shift : there is no clear blue shift.

In this thesis, we have set up a SiO2 sputter system. We applied sputter techniques for quantum well intermixing (QWI) process to increase the bandgap of the quantum well structure. The samples with multiple quantum wells were grown by our team members using molecular beam epitaxy system, and the MQW structure were grown by MOCVD. Before sputtering, some samples will use ICP to enhance the vacancy on the surface. First, we will sputter SiO2 on the surface of sample. After SiO2 film deposition, the samples were annealed by Rapid Thermal Process. And ordinary annealing were about 700¢J~800¢J. A later period, the annealing temperatures will be above 850¢J. Room-temperature PL (Photoluminescence) measurements were used to study the blue shift and intensity change after QWI process. And we will do the mesa process to measure the characteristic of optoelectronics. If the conditions are RF power = 100W, sputter time = 30 min, ICP enhance 250W for 2 min, annealing temperature = 825¢J, annealing time = 60 sec. The PL signal have a blue shift of 64nm(wavelength from 1506nm to 1444nm).When annealing temperature =700¢J, and annealing time = 60 sec, we have a blue shift of 12nm(wavelength from 1572nm to 1560nm) on the C116 sample. We do the mesa process on the MQW which contain P and it have a large blue shift. After the process, we success to compare the different between EL and Photocurrent. But the structure of samples which certain Al do not have a apparent blue shift. And the annealing temperature is too large, samples will be damaged. We think that the reason have relation to materials of the sample.

We measure the energy gap of two-dimensional electron gas in AlAs0.56Sb0.44/Ga0.47In0.53As at low temperature by photoluminescence measurement. We intend to observe the intersubband transition in these samples, especially the first and second subband. We have discovered that the sample ( AlAs0.56Sb0.44/Ga0.47In0.53As ) has three subband by SdH and electron density will increase with illumination time. Although we did not observe the intersubband transition in the experiment, we did know the performance and controls about TRIAX320 monochrometer. It means we could measure the better result in further.

Abstract The purpose of this thesis is to fabricate l = 1.55mm ridge waveguide spot size converter lasers for high laser-to-fiber coupling. The laser structure design includes the lateral and vertical directions. In the vertical aspect, we use six asymmetric InGaAsP/InP quantum wells of 50, 50, 100, 100, 150, 150Å. The asymmetric multi-quantum-well structure is designed to gather the optical field in the 150Å-wide quantum wells. Besides, we add a passive waveguide near the 150Å-wide quantum wells to expand optical field profile. In the lateral aspect, we use tapered ridge waveguides which have two different fashions: one is tapered down from 2.5mm to 1mm, and the other is tapered up from 2.5mm to 4mm. The results show that the tapered-up ridge waveguide laser has a CW operation with Ith = 34mA and diverge angles of 14¢X¡Ñ36¢X (q//¡Ñq^) at room temperature. The tapered-down ridge waveguide laser exhibits only a pulsed operation at room temperature. At lower temperature T = 13¢XC, the tapered-down laser has a CW operation of Ith = 36mA and diverge angles of 14¢X¡Ñ36¢X(q//¡Ñq^). From I-V and C-V measurements, we attribute the heating problem to the large series resistance caused by the incorrect n-type doping profile in the epitaxy process.

Abstract In this thesis, we have setup a photoluminescence (PL) measurement system to investigate the quantum well intermixing (QWI) effects on semiconductor multiple quantum-well (MQW) structures. The measured samples include 1.3mm and 1.55mm InGaAsP MQW laser structures grown by MOCVD, and 1.55mm InGaAlAs MQW structures by MBE. The QWI process was performed by rapid thermal annealing at 600¢J~800¢J in 1 min with a ~1300Å SiO2 layer sputtered on the semiconductor surface. Following the SiO2 sputtering and thermal annealing, room-temperature PL measurements were used to study the QWI effect. The result shows that the PL intensity is reduced for the MOCVD samples, while the MBE samples have up to 47 times increase of PL intensity. After QWI process, all the samples have a blue-shift in PL spectra. The 1.55mm InGaAsP laser structures by MOCVD have a maximum blue-shift of 34nm, and the MBE samples of 12nm after 800¢J annealing.

The two-dimensional electron system in strongly coupled GaAs/Al0.3Ga0.7As double quantum wells has been studied by Shubnikov-de Haas¡]SdH¡^measurements. The degenerate subbands of the double quantum wells are lift into two subbands with a symmetric or anti- symmetric z-direction wave function. We observed that the SdH oscillation due to the second subband of anti-symmetric wave function. The effective mass of the second subband is linearly dependent on the magnetic field range from 0.680 T to 1.964 T. The mass enhancement for the double-quantum-well with an equal well thickness is greater than that with an unequal one. This mass enhancement is attributed to the electron-electron interaction.

From PL spectrum of InGaAsN LD structures grown by MOCVD and MBE, we observe remarkable red shift of the wavelength after the addition of small concentration of nitrogen. For MOCVD growth, the concentration of nitrogen increases from 0.3% to 0.5%, and the wavelength improve from 1.17£gm to 1.202£gm. For MBE growth, the concentration of nitrogen increases from 2.1% to 2.6%, and the wavelength improve from 1.196£gm to 1.289£gm. When the concentration arrived 3%, we find the wavelength already unable to improve to long wavelength. We also observed the changes the PL peak like S-shaped from temperature-depentent PL spectrum. For the photocurrent and electroabsorption measurement, we prepared two the same concentration of nitrogen 2.1% samples, but different structures ,one is TR538 single quantum well structure, the other is TR515 double quantum well structure. The e1-hh1transition can be observed clear at £f=1.192 of TR515, but it was unapparent for TR538. Now, let us focus on the photocurrent and £G£\ signal of the fundamental e1-hh1 transitions for the largest reverse bias voltage swing(0-6v) , the maximum absorption changes of around 5394cm-1 for TR538 and 14439cm-1 for TR515. The refractive index changes of 0.019 for TR538 and 0.035 for TR515.

Hedonism is not terribly popular as a theory of well-being. And there are good reasons to question whether hedonism even supplies the best account of happiness. Yet hedonism captures something important, and it will be the goal of this essay to articulate just what that is. I suggest that hedonism provides the best account of phenomenal wellbeing (PWB). PWB is a restricted form of well-being that relates to the quality of the experience of a life—or, in other words, the quality of one’s phenomenal life. If wellbeing is characterized as “how well one’s life goes,” then PWB is “how well one’s life goes for her, from the inside.” In rating a life’s PWB, the life is judged solely on the basis of the contents of the experience of that life rated against the experience of the individual’s other possible lives. Unlike well-being, PWB is guaranteed to track more robust experiential benefits that a person gets out of living a life. In this work, I discuss the concept of well-being, including the feature of subjectrelativity that is sometimes ascribed to it; then, after introducing the concept of a phenomenal life, I develop the concept of phenomenal well-being. I propose what I take to be the best available account of PWB, which involves the hedonistic concept of satisfaction. An epistemic model of life-comparison (inspired by Peter Railton’s full information account of well-being) on which phenomenal lives are judged on the criterion of satisfaction is presented, followed by some objections, and replies, to PWB as satisfaction. Finally, some rival accounts of PWB are discussed and critiqued—notably, an account of cognitive life-satisfaction that resembles theories of “life-satisfaction” in happiness theory. The claim is that hedonism supplies the best answer to what makes the experience of our lives go best for us. In the closing chapter, I make some suggestions concerning the significance of this fact.

This dissertation is composed of three parts of major contributions: In Chapter II, we developed a new conceptual model and derived a new semi-analytical model for flow to a horizontal well beneath a water reservoir. Instead of treating the leakage from aquitard as a source term inside the aquifer which is called Hantush’s assumption (1964), we linked flows in aquitard and aquifer by the idea of continuity of flux and drawdown. The result in this chapter is compared with that of Zhan and Park in 2003 which Hantush’s assumption is adopted at various hydraulic and well configurations. It shows that Hantush’s assumption becomes inaccurate in regions where vertical velocity components are significant. In Chapter III, we deal with the interaction of an aquifer with two parallel surface water bodies such as two streams or canals. In this chapter, new closed-form analytical and semi-analytical solutions are acquired for the pumping induced dynamic interaction between two streams and ground water for two different cases. In the first case, the sediment layers separating the streams from the aquifer ground water do not exist. In the second case, the two low permeable layers are considered. The effect of aquitard and water right competition is addressed in this chapter. This model can be used for interpreting and deriving hydrologic parameters of aquitard and aquifer when pumping occurs between two channels. It can also be used to predict stream depletion which is essential for water management and ecology conservation. In Chapter IV, we investigated the three dimensional upconing due to a finite-length of horizontal well and its critical conditions. The results are compared with those of vertical wells. The critical condition which includes the critical rise and the critical time at a certain pumping rate depends on the well length, the initial interface location, the well location, and the pumping rate. Our results show that horizontal well might be a better tool for coastal groundwater resources development. In real field applications, installing long wells as shallow as possible is always desirable for sustaining long periods of pumping with significant rates.

The demand of oil and gas resources is high and the forecasts show a trend for higher requirements in the future. More unconventional resource exploitation along with an increase in the total recovery in current producing fields is required. At this pivotal time the role of emerging technologies is of at most importance. Smart or intelligent well technology is one of the up and coming technologies that have been developed to assist improvements in field development outcome. In this paper a comprehensive review of this technology has been discussed. The possible reservoir environments in which smart well technology could be used and also, the possible benefits that could be realized by utilizing smart well technology has been discussed. The economic impact of smart well technology has been studied thoroughly. Five field cases were used to evaluate the economics of smart well technology in various production environments. Real field data along with best estimate of smart well technology pricings were used in this research. I have used different comparisons between smart well cases and conventional completion to illustrate the economic differences between the different completion scenarios. Based on the research, I have realized that all the smart well cases showed a better economic return than conventional completions. The offshore cases showed a good economic environment for smart well technology. Large onshore developments with smart well technology can also provide a lucrative economic return. These situations can increase the overall economic return and ultimate recovery which will assist in meeting some of the oil demand around the globe.