Article

Inhibited Spontaneous Emission in Solid-State Physics and Electronics

Physical Review Letters (Impact Factor: 7.73). 01/1987; 58:2059-2062. DOI: 10.1103/PhysRevLett.58.2059

ABSTRACT It has been recognized for some time that the spontaneous emission by atoms is not necessarily a fixed and immutable property of the coupling between matter and space, but that it can be controlled by modification of the properties of the radiation field. This is equally true in the solid state, where spontaneous emission plays a fundamental role in limiting the performance of semiconductor lasers, heterojunction bipolar transistors, and solar cells. If a three-dimensionally periodic dielectric structure has an electromagnetic band gap which overlaps the electronic band edge, then spontaneous emission can be rigorously forbidden.

4 Bookmarks
 · 
184 Views
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Left-handed materials have superlensing effects that enable them to surmount the optical diffraction limit. A photonic crystal is able to mimic some properties of all-angle left-landed materials. In this study, the all-angle negative refraction criteria of photonic crystals are evaluated. The MIT Photonic-Bands program is employed to calculate the band structure of walled honeycomb photonic crystals, and the finite-difference time-domain method is used to provide a snapshot of the electric field distribution inside and outside the honeycomb pho-tonic crystals. The results indicate that the all-angle negative refraction phenomena of the honeycomb photo-nic crystals are correlated with the orientation of the photonic crystals. Furthermore, the role of the uncoupled modes varies based on their orientation to the all-angle negative refraction photonic crystals, in one case as-sisting negative refraction and in the other case preventing it. The results suggest that symmetric properties should not be ignored when considering the negative refraction of photonic crystals.
    Journal of the Optical Society of America B 01/2065; 476052983620(260):350-3618. · 2.21 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: The effects of electric and magnetic loss factors on zero-mu and zero-epsilon gaps in a one-dimensional lossy photonic crystal composed of double-negative and double-positive materials are theoretically investigated by employing the characteristic matrix method. This study contradicts the previous reports as it indicates that by applying the inevitable factors of electric and magnetic losses to the double-negative material, the zero-mu and zero-epsilon gaps appear simultaneously in the transmission spectrum, being independent of the incidence angle and polarizations. Moreover, the results show that these gaps appear not only for an oblique incidence but also in the case of normal incidence, and their appearance at the normal incidence is directly related to the magnetic and electric loss factors. Besides, the results indicate that as the loss factors and angle of incidence increase, the width of both gaps also increases.
    Physica B Condensed Matter 12/2014; 454:170–174. · 1.28 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: We describe photonic crystal microcavities with very strong light-matter interaction to realize room-temperature, equilibrium, exciton-polariton Bose-Einstein condensation (BEC). This is achieved through a careful balance between strong light-trapping in a photonic band gap (PBG) and large exciton density enabled by a multiple quantum-well (QW) structure with moderate dielectric constant. This enables the formation of long-lived, dense 10~$\mu$m - 1~cm scale cloud of exciton-polaritons with vacuum Rabi splitting (VRS) that is roughly 7\% of the bare exciton recombination energy. We introduce a woodpile photonic crystal made of Cd$_{0.6}$Mg$_{0.4}$Te with a 3D PBG of 9.2\% (gap to central frequency ratio) that strongly focuses a planar guided optical field on CdTe QWs in the cavity. For 3~nm QWs with 5~nm barrier width the exciton-photon coupling can be as large as $\hbar\Ome=$55~meV (i.e., vacuum Rabi splitting $2\hbar\Ome=$110~meV). The exciton recombination energy of 1.65~eV corresponds to an optical wavelength of 750~nm. For $N=$106 QWs embedded in the cavity the collective exciton-photon coupling per QW, $\hbar\Ome/\sqrt{N}=5.4$~meV, is much larger than state-of-the-art value of 3.3~meV, for CdTe Fabry-P\'erot microcavity. The maximum BEC temperature is limited by the depth of the dispersion minimum for the lower polariton branch, over which the polariton has a small effective mass $\sim 10^{-5}m_0$ where $m_0$ is the electron mass in vacuum. By detuning the bare exciton recombination energy above the planar guided optical mode, a larger dispersion depth is achieved, enabling room-temperature BEC.
    08/2014;