The authors demonstrate the selective postgrowth band gap engineering and the fabrication of band gap tuned laser in InAs–InAlGaAs quantum-dash lasers grown on InP substrate. The process utilizes nitrogen implantation to induce local defects and to enhance the group-III intermixing rate spatially upon the thermal annealing. Compared with the as-grown laser, intermixed laser with wavelength shifted by 127nm shows a 36% reduction in threshold current density and produces a comparable slope of efficiency. The integrity of the intermixed material is retained suggesting that intermixing process paves way to planar, monolithic integration of quantum-dash-based devices.
We present a microstructured fiber whose 9 µm diameter core consists in three concentric rings made of three active glasses having different rare earth oxide dopants, Yb3+/Er3+, Yb3+/Tm3+ and Yb3+/Pr3+, respectively. Morphological and optical characterization of the optical fiber are presented. The photoluminescence spectrum is investigated for different pumping conditions using a commercial 980 nm laser diode. Tuning of the RGB (or white light) emission is demonstrated not only by adjusting the pump power but also by using an optical iris as spatial filter which, thanks to the microstructured core, also acts as a spectral filter.
Abstract-The mid-IR spectral range is of particular interest for two main reasons: many molecules exhibit signature optical absorptions in this wavelength range and specific transmission windows within these wavelengths are available in the Earth's atmosphere. Options for compact, reliable, high power mid-IR optical sources are currently rather limited by the difficulty of finding host materials that are both transparent in the mid-IR wavelengths range and sufficiently stable, robust and easy to fabricate. In this paper the relevant glass host materials suitable for the development of mid-IR coherent sources based on rare earths doping are briefly reviewed. The current state of the art in mid-IR fiber laser and supercontinuum sources is also presented.
Abstract-Solar pumped laser (SPL) can find wide applications in space missions, especially for long lasting ones. In this paper a new technological approach for the realization of a SPL based on fiber laser technology is proposed. We present a preliminary study, focused on the active material performance evaluation, towards the realization of a Nd 3+ -doped fiber laser made of phosphate glass materials, emitting at 1.06 μm. For this research several Nd 3+ -doped phosphate glass samples were fabricated, with concentration of Nd 3+ up to 10 mol%. Physical and thermal properties of the glasses were measured and their spectroscopic properties are described. The effect of Nd 3+ doping concentration on emission spectra and lifetimes was investigated in order to study the concentration quenching effect on luminescence performance.
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