C.Y. Hu

Publications (3)0 Total impact

• Conference Proceeding: CQED-Enhanced Single Photon Sources From InGaAs Quantum Dots

  C.Y. Hu, R. Gibson, J.A. Timpson, S. Lam, A.M. Fox, M.S. Skolnick, M. Hopkinson, A. Tahraoui, J.G. Rarity
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  ABSTRACT: Historically non-classical sources of single photons have been used to test quantum mechanics and to develop the field of quantum optics. Nowadays the single photon source has become a critical device for quantum communications and optical quantum information processing [Knill, et al., 2001]. A single photon source emits one photon at a time, and its quality can be evaluated by three parameters: quantum efficiency, multi-photon probability, and photon distinguishability. Among the different types single photon sources, InGaAs/GaAs quantum dots (QDs) are a promising solid state candidate showing high quantum efficiency, no bleaching effect, long-term stability, capable of high repetition rate, and compatible with standard semiconductor processing techniques. Furthermore, QDs can be embedded in micro-cavities or photonic crystal nano-cavities by in situ growth, and thus cavity quantum electrodynamics (CQED) can be exploited to improve the performance of QD-based single photon sources in all aspects mentioned above [Santori, et al., 2002].
  Lasers and Electro-Optics, 2007 and the International Quantum Electronics Conference. CLEOE-IQEC 2007. European Conference on; 07/2007
• Conference Proceeding: Experiments Versus Modelling in Quantum Dot Pillar Microcavities

  J.G. Rarity, Y.-L.D. Ho, R. Gibson, C.Y. Hu, M.J. Cryan, I.J. Craddock, C.J. Railton, D. Sanvitto, A. Darei, M. Hopkinson, J.A. Timpson, A.M. Fox, M.S. Skolnick
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  ABSTRACT: 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
  Transparent Optical Networks, 2006 International Conference on; 07/2006
• Conference Proceeding: Quantum-dots in micro-pillar micro-cavities: experiment and theory

  C.Y. Hu, R. Gibson, Y.-L.D. Ho, M.J. Cryan, I.J. Craddock, C.J. Railton, D. Sanvitto, A. Daraei, M. Hopkinson, M.S. Skolnick, J.G. Rarity
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  ABSTRACT: This work reports on the modelled micro-pillar micro-cavities made of III-V semiconductor materials (AlAs/GaAs) with quarter-wavelength-period stacks resonant at wavelengths in the 900-1000 nm region using the 3-D finite-difference time-domain (FDTD) method. A broadband dipole source is placed in the centre of the cavity and a short few-cycle excitation pulse is input to model quantum dot emission. The cavity then rings at its resonant frequency and the cavity ring down is monitored using a probe above the pillar. This allows the resonances of the various waveguide modes in the cavity to be determined.
  Quantum Electronics Conference, 2005. EQEC '05. European; 07/2005