Novel devices and heterostructures based on modulated dielectric properties of materials.

摘要

The ability to alter characteristics of light propagating through the material systems with modulated dielectric properties has become a fundamental concept in the design of many recent optoelectronic devices. The idea of physical modulation of the dielectric properties is used in a broad class of the devices where different materials are periodically arranged to provide the desired control and manipulation of light. Physical modulation is not the only way to induce changes in the dielectric properties of the material system. There exists an entire class of electro-optic materials that change their dielectric properties under the application of the electric field.; The present work is a theoretical simulation and calculations of optical properties as required for novel optoelectronic devices based on the physical and field induced modulations of the dielectric properties of a medium. One-dimensional periodic arrangement of materials is a key component in the heterostructure laser design. Such structures have been simulated for Vertical Cavity Surface Emitting Lasers operating at 400nm and 1.55μm. The selection of the optimal materials for two Bragg mirror systems was made possible as the result of the detailed study of the optical properties of the group III-V and III-V nitride semiconductor alloys. The resulting optimized surface emitting lasers predicts an improvement in the performance.; Physical modulation of the dielectric properties in two dimensions has been applied in the design and simulation of a novel photonic crystal for application in a lossless waveguide.; In addition to physical modulation, we have applied field induced modulations of the dielectric properties of atypical nonlinear optical material and have designed and simulated a novel spatial phase modulator. The new modulator design is predicted to overcome existing limitations based on high operating voltages, large device size and non-monolithic integration. The device, which may be used for beam steering applications has many potential attractive features such as its ability to steer over a variety of deflection angles and to change the deflection angle of the incoming beam by programming the applied bias voltages without changing the geometry of the electrodes.