Quantum design of a 1.3 μm InGaPAs semiconductor laser
Semiconductor wafer growth can now produce heterostructures of very high quality with stoichiometrically correct growth of individual monolayers. Despite significant advances in MBE and MOCVD growth technologies, a critical void has remained in predicting the performance of final packaged functional amplifier or laser devices. The lack of predictive semiconductor device design and growth monitoring capability can be traced to the extreme complexity of calculating the semiconductor optical response and radiative-nonradiative recombination rates from first principles. Considering the critical role of the above recombination processes in not only, determining gain and slope efficiency but, also all dynamic properties (modulation rates, gain switching, injection locking etc) of SOAs and SLs, it is clear that the impact of this work reaches well beyond the accurate prediction of an L-I characteristic.
Closed-loop design of a semiconductor laser
We present an overview of a novel first principles quantum approach to designing and optimizing semiconductor QW material systems for target wavelengths. Using these microscopic inputs as basic building blocks we predict the L-I characteristic for a low power InGaPAs ridge laser without having to use adjustable fit parameters. Finally we employ these microscopic inputs to develop sophisticated simulation capabilities for designing and optimizing end packaged high power laser structures. As an explicit example of the latter, we consider the design and experimental demonstration of a vertical external cavity semiconductor laser (VECSEL).
Numerical Simulation for Natural State of Two-Phase Liquid Dominated Geothermal Reservoir with Steam Cap Underlying Brine Reservoir
Hydrothermal reservoir which liquid-dominated hydrothermal reservoir is a type of geothermal reservoir that most widely used for power plant. The exploitation of mass and heat from the geothermal fluid will decrease the pressure in the reservoir over time. Therefore the pressure drop in the reservoir will have an impact on the formation of boiling zones or boiling will increase. The impacts are an increase in the fraction of steam, dryness, in the reservoir and with good vertical permeability will form a steam cap underlying the brine reservoir. The two- phase liquid dominated reservoir is sensitive to the porosity and difficult to assign average properties of the entire reservoir when there is boiling zone in some area of the reservoir. These paper showed successful development of two-phase liquid dominated geothermal reservoir and discussed the formation of steam cap above brine reservoir through numerical simulation for state natural conditions. The natural state modeling in steam cap shows a match with the conceptual model of the vapor-dominated developed. These paper also proofed the presence of transition zone, boiling zone, between steam cap and brine reservoir.