טכניון מכון טכנולוגי לישראל
הטכניון מכון טכנולוגי לישראל - בית הספר ללימודי מוסמכים  
M.Sc Thesis
M.Sc StudentAmir Sivan
SubjectEnhancement of Superradiant Emission of Quantum Sources
by Coupling to Nanostructured Media
DepartmentDepartment of Electrical Engineering
Supervisor Full Professor Orenstein Meir
Full Thesis textFull thesis text - English Version


Abstract

I develop a theory for cooperative spontaneous emission of an ensemble of quantum emitters near matter, which is consistent with the quantum mechanical treatment originally performed by Dicke and incorporates the Huttner-Branett quantization scheme for description of material absorption in the quantum mechanical picture. The model considers both the effects of building of inter-emitter correlation over time through transitions via the common field, and of geometry-induced spatial correlation. The presence of matter alters the Local Density of States (LDOS) in a manner predictable by classical electromagnetism, resulting in a modified decay rate and emission intensity for the entire ensemble relative to those of spontaneous emission in free space. This influence is evident in the model presented in this thesis because the function of the superradiant total emission is separable into a quantum mechanical time-dependent part and a classical space-dependent part, both being functions of the LDOS. Two distinct radiative emitter-far field coupling mechanisms, which together account for the superradiant emission, are obtained and discussed. Numerical calculations are demonstrated for superradiating emitters near silver and near-zero epsilon (NZE) materials. In the analyzed cases, it is found that a silver sphere augments the superradiant far-field intensity and rate by up to 400% and 1,000% respectively, while NZE sphere enhances the far-field intensity and rate of the superradiance by approximately 1,400% and 400%, respectively.