Optical Characterisations of Bi-Phosphosilicate Fiber for O Band Amplification

We report on the optical properties of Bi-doped phosphosilicate fiber. The fiber with a core and a clad diameter of 7.75 µm and 125 µm, respectively, is fabricated in-house using the modified chemical vapor deposition (MCVD) with in-situ solution doping technique. The spectroscopic properties of the fabricated fiber are characterized in terms of absorption, emission and lifetime. The lifetime decay is measured to be 800 µs; indicating a good potential optical amplification in the range of 1300 to 1500 nm. A Bismuth-doped fiber amplifier (BDFA) operating within the O-band region was successfully demonstrated. At 1340 nm, a 14.8 dB gain is achieved with 300 mW pumping power.

Solution-processed, semitransparent organic photovoltaics integrated with solution-doped graphene electrodes

In this work, by applying a transfer method simultaneously with a solution doping process for graphene as top electrodes, we demonstrate a solution-processed semitransparent organic photovoltaics (OPV). The work function of doped graphene under various doping conditions was investigated via photoemission spectroscopy. The transparent device was fabricated using PEDOT-doped graphene as electrodes, which provide an energetically favorable band alignment for carrier extractions. The solution-processed semitransparent organic photovoltaics exhibit the power conversion efficiency (PCE) of 4.2%, which is 85.7% of the PCE of control devices based on metallic reflecting electrodes, while maintaining good transparency at most visible wavelengths.

Fabrication of Active Polymer Optical Fibers by Solution Doping and Their Characterization

This paper employs the solution-doping technique for the fabrication of active polymer optical fibers (POFs), in which the dopant molecules are directly incorporated into the core of non-doped uncladded fibers. Firstly, we characterize the insertion of a solution of rhodamine B and methanol into the core of the fiber samples at different temperatures, and we show that better optical characteristics, especially in the attenuation coefficient, are achieved at lower temperatures. Moreover, we also analyze the dependence of the emission features of doped fibers on both the propagation distance and the excitation time. Some of these features and the corresponding ones reported in the literature for typical active POFs doped with the same dopant are quantitatively similar among them. This applies to the spectral location of the absorption and the emission bands, the spectral displacement with propagation distance, and the linear attenuation coefficient. The samples prepared in the way described in this work present higher photostability than typical samples reported in the literature, which are prepared in different ways.

On the Enlargement of the Emission Spectra from the 4I13/2 Level of Er3+ in Silica-Based Optical Fibers through Lanthanum or Magnesium Co-Doping

Improving optical fiber amplifiers requires the elaboration and use of new materials and new compositions. In this sense, we prepared erbium-doped optical fiber samples that were co-doped with magnesium or lanthanum by gradual-time solution doping. Doping concentrations and thermal processes induce the formation of nanoparticles. The effect of lanthanum and magnesium contents on the width of the spontaneous emission of the 4 I 13 / 2 level of Er 3 + was characterized in the nanoparticle-rich fiber samples. For that purpose, the width was characterized by the effective linewidth and the full-width at half-maximum (FWHM). The results indicate the robustness of the effective linewidth to strong variations in the intensity profiles of the 4 I 13 / 2 spontaneous emission. Increasing the doping concentrations of both magnesium and lanthanum increases the FWHM and the effective linewidth, along with optical losses. Results show that the fabrication of nanoparticle-rich optical fibers through lanthanum or magnesium doping induces an FHWM broadening of 54% and 64%, respectively, or an effective linewidth broadening of 59% (for both elements) while maintaining a transparency that is compatible with fiber laser and amplifier applications.