Calculation of atomic spontaneous emission rate in 1D finite photonic crystal with defects

We derive the expression for spontaneous emission rate in finite one-dimensional photonic crystal with arbitrary defects using the effective resonator model to describe electromagnetic field distributions in the structure. We obtain explicit formulas for contributions of different types of modes, i.e. radiation, substrate and guided modes. Formal calculations are illustrated with a few numerical examples, which demonstrate that the application of effective resonator model simplifies interpretation of results.Comment: Cent. Eur. J. Phys, in pres

Deep Defects in Low-Temperature GaAs

Conductivity of GaAs layers grown by molecular beam epitaxy at low substrate temperature (190-200°C) and then annealed at few different temperatures (between 300 and 600°C) were studied. It was confirmed that electron transport is due to hopping between arsenic antisite defects. Parameters describing hopping conductivity and their dependence on temperature of annealing are discussed. Other deep defects with activation energies of 0.105, 0.30, 0.31, 0.47, 0.55 eV were found using photoinduced current transient spectroscopy measurements

FFirst TSC and DLTS Measurements of Low Temperature GaAs

The first thermally stimulated current (TSC) and deep level transient spectroscopy (DLTS) studies performed on GaAs grown by molecular beam epitaxy (MBE) at low substrate temperatures (LT GaAs) are reported. TSC experiments, conducted on as grown and 400-580°C annealed layers showed domination of arsenic antisite (EL2-like) defect and supported its key role in hopping conductivity. DLTS studies, performed on Si doped and annealed at 800°C layers revealed substantially lower concentration of EL2-like defect and an electron trap of activation energy ΔE = 0.38 eV was found

Mode formation in broad area quantum dot lasers at 1060 nm

An analysis of the transverse and longitudinal mode structure of broad area quantum dot lasers emitting at 1060 nm is presented. In particular, temperature is shown to play an important role in the stabilisation of the transverse mode structure of the devices. In addition, the investigation of the interaction between these transverse modes, through the measurement of the spatial intensity correlation, shows that the laser retains some modal properties in the unstable regime. Finally, measurements of spectral correlations between longitudinal mode groups display a strong dependency on their respective transverse mode structures indicating the importance of spatial overlap

Identification of Residual Impurities in Si-Doped MBE Grown GaAs

The changes of dopant vaporization enthalpy in GaAs:Si grown by molecular beam epitaxy revealed the presence of residual donors related to group VI elements. This has been confirmed by deep level transient spectroscopy studies of AlGaAs:Si layers grown in the same MBE system. It is argued that a commonly observed deep trap labelled E2 is probably related to Te, Se or S. The measurements have been performed on near-ideal Al Schottky barriers grown in situ by MBE