Recently, single photon sources have been realised by coupling InAs quantum-dots into circular micro-pillar microcavities based on distributed Bragg reflectors (DBRs). These sources can be highly efficient because the high semiconductor refractive index collects a large fraction of the spontaneous emission into the waveguide mode. We have modelled emission from circular, square, elliptical and rectangular pillars using the finite difference time domain (FDTD) method and see enhanced emission into the cavity mode and improved efficiency for coupling light out of the microcavity. The cavity Q-factors can be very high even when the pillar diameter (dimension) is comparable to the emission wavelength. In the elliptical and rectangular cavities the modes separate (in frequency) into a high-Q resonance with polarisation parallel to the long axis and a lower Q-factor resonance with polarisation orthogonal to the long axis. We compare our modelling with preliminary measurements made on micro-pillar microcavity samples containing a layer of low density InAs dots at the cavity centre
Sponsorship: We acknowledge funding from EPSRC IRC in Quantum Information Processing (www.qipirc.org), EPSRC grant 1-phot and EU:FP6 Integrated project Quantum Applications (www.qubitapplications.com).
This material is posted here with permission of the IEEE. Such permission of the IEEE does not in any way imply IEEE endorsement of any of the University of Bristol's products or services. Internal or personal use of this material is permitted. However, permission to reprint/republish this material for advertising or promotional purposes or for creating new collective works for resale or redistribution must be obtained from the IEEE by writing to email@example.com.
By choosing to view this document, you agree to all provisions of the copyright laws protecting it.
Name of Conference: International Conference on Transparent Optical Networks
Venue of Conference: Nottingham, UK
- Bragg reflection, quantum dots, spontaneous emission modification, optical microcavities, cavity quantum electrodynamics, light confinement