Transmission Properties Of Photonic Quantum Wells

In this thesis,we investigate the transport of light through two-dimensional photonic-well structures by the R-matrix algorithm.Our arm is to supply physical models and make theoretical validity in designing discrete-frequency-pass filters with better properties.Besides,the quantum transport of electrons through an Aharonov-Bohm(AB) ring with the Rashba spin-orbit coupling is also investigated in terms of the S-matrix method.It is shown that this mesoscopic device indeed can act as a spin-filter and a spin polarizer or splitter.Basing on the photonic band gap,the photonic quantum well structure consists of the two-dimensional photonic crystal barrier series with homogeneous transparent media in between.We study the transmission spectra of photons through a coupled double-well system.The resonant frequencies can be controlled by the well-width,barrier-height and media in the well.Such structures are shown to act as the discrete-frequency-pass filters.Further,resonant transmission of light through multiple well structures is investigated.We find that the transmission probability displays a typical pattern in the propagation forbidden band,which shows n-fold peak splitting in an n-well system.A higher permittivity value of the transparent well-medium results in denser resonance peaks with frequencies shifted towards the red and furthermore the number of peaks can be greatly suppressed when the normal well-medium is replaced by left-handed materials.We observe a new distortion of resonance-peak splitting with alternately placing the normal and the left-handed media in two wells completely different from the distortion induced by the asymmetry of well-width with the same kind of well-media in both wells.Based on analytical calculation of the transmission probability in one-dimensional photonic-crystal wells,the new observation is understood as a result of destructive interference in the left-handed and normal well-media. Furthermore,resonance frequencies can still be adjusted by changing the order of arrangement of different media in the wells.Finally,the quantum transport of electrons through a three-lead ballistic Aharonov-Bohm(AB) ring with the Rashba spin-orbit interaction is revisited in terms of the S-matrix method.The spin-resolved transmission probabilities are predicted to depend on the AB flux and Rashba coupling strength.In consequence tuning one of these parameters allows us to rotate or polarize the spin states of the carriers efficiently.This supplies a theoretical validity in designing a spin-filter and a spin polarizer or splitter with better properties.