In this work, the construction of a single stage L-band erbium-doped fiber amplifier which incorporates a short 5.1 m erbium doped fiber coil is described. Gain and noise figure measurements as a function of forward, backward and counter-propagating CW 1480 nm pumping schemes at different pump power levels are presented. Further, the Erbium Doped Fiber Amplifier (EDFA) power conversion efficien...

We report growth and characterization of heavily boron-doped 3C-SiC and 6H-SiC and Al-doped 3C-SiC. Both 3C-SiC:B and 6H-SiC:B reveal type-I superconductivity with a critical temperature Tc=1.5 K. On the other hand, Al-doped 3C-SiC (3C-SiC:Al) shows type-II superconductivity with Tc=1.4 K. Both SiC:Al and SiC:B exhibit zero resistivity and diamagnetic susceptibility below Tc with effective hole...

The magnetic phase diagrams, and other physical characteristics, of the hole– doped La2−xSrxCuO4 and electron–doped Nd2−xCexCuO4 high–temperature superconductors are profoundly different. Given that it is envisaged that the simplest Hamiltonians describing these systems are the same, viz. the t − t − J model, this is surprising. Here we relate these physical differences to their ground states’ ...

A mesoscopic nitrogen-doped TiO2 sphere has been developed for a quasi-solid-state dye-sensitized solar cell [DSSC]. Compared with the undoped TiO2 sphere, the quasi-solid-state DSSC based on the nitrogen-doped TiO2 sphere shows more excellent photovoltaic performance. The photoelectrochemistry of electrodes based on nitrogen-doped and undoped TiO2 spheres was characterized with Mott-Schottky a...

The phase diagram of order parameters for pairing and phase coherence in hole-doped cuprates is discussed. By examining carefully some recent inelastic neutron scattering data obtained on hole-doped cuprates and heavy fermion compound UPd2Al3 in which the superconductivity is mediated by spin fluctuations, we conclude that the coherent gap in hole-doped cuprates has most likely the magnetic ori...

We have chemically polymerized pyrrole in the presence of Sn-doped TiO2 nanoparticles (NPs) and TiO2 (NPs) which act as a protective pigment. Field emission scanning electron microscopy (FESEM) and transmission electron microscopy (TEM) results show a core–shell structure of pigments in which TiO2 and Sn-doped TiO2 NPs have a nucleus effect and caused a homogenous PPy core–shell type morphology...

Tm3+-doped fiber is very suitable for producing ~2-μm laser emission due to its several unique advantages. First, Tm3+-doped fiber has a strong absorption spectrum that has good overlap with the emission spectrum of commercially available AlGaAs laser diodes. Second, the specific energy-level structure of Tm3+ ions provides the Tm3+-doped fiber laser (TDFL) quantum efficiency close to two throu...

Far infrared ~FIR! absorption, reflection, and transmission in heavily doped p-GaAs multilayer structures have been measured for wavelengths 20–200 mm and compared with the calculated results. Both Be ~in the range 3310– 2.6310 cm! and C (1.8310– 4.7310 cm)-doped structures were studied. It is found that the observed absorption, reflection, and transmission are explained correctly by the model ...

Tm3+-doped fiber is very suitable for producing ~2-μm laser emission due to its several unique advantages. First, Tm3+-doped fiber has a strong absorption spectrum that has good overlap with the emission spectrum of commercially available AlGaAs laser diodes. Second, the specific energy-level structure of Tm3+ ions provides the Tm3+-doped fiber laser (TDFL) quantum efficiency close to two throu...

Nitrogen doped mesoporous TiO(2) was prepared via a modified two-step hydrothermal route. In contrast to undoped mesoporous TiO(2), nitrogen doped mesoporous TiO(2) has superior photocatalytic activity under both UV and visible light irradiation. Photoluminescence spectra reveal that nitrogen doped mesoporous TiO(2) possesses abundant surface states, which can play a vital role in trapping phot...