Janne Puustinen

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Composting of contaminated soil in biopiles is an ex situ technology, where organic matter such as bark chips are added to contaminated soil as a bulking agent. Composting of lubricating oil-contaminated soil was performed in field scale ( [Formula: see text] m(3)) using bark chips as the bulking agent, and two commercially available mixed microbial inocula(More)
We demonstrate a 1.32 μm mode-locked bismuth fiber laser operating in both anomalous and normal dispersion regimes. In anomalous dispersion regime, achieved by using 13 nm/cm linearly chirped fiber Bragg grating, the laser exhibits multiple soliton operation with pulse duration of 2.51 ps. With the net normal cavity dispersion, the single-pulse operation(More)
We report the formation and phase transformation of Bi-containing clusters in GaAs(1-x)Bi(x) epilayers upon annealing. The GaAs(1-x)Bi(x) layers were grown by molecular beam epitaxy under low (220 °C) and high (315 °C) temperatures and subsequently annealed using different temperatures and annealing times. Bi-containing clusters were identified only in the(More)
In this study, we investigate the effect of annealing and nitrogen amount on electronic transport properties in n- and p-type-doped Ga0.68In0.32NyAs1 - y/GaAs quantum well (QW) structures with y = 0%, 0.9%, 1.2%, 1.7%. The samples are thermal annealed at 700°C for 60 and 600 s, and Hall effect measurements have been performed between 10 and 300 K. Drastic(More)
In this work the photoconductivity of a p-i-n Ga<inf>0.952</inf>In<inf>0.048</inf>N<inf>0.016</inf>As<inf>0.984</inf>/GaAs multiple quantum well (MQW) structure is investigated as a function of temperature. At low temperatures step-like increases are observed in the devices I&#x2013;V characteristic when illuminated with a 950nm wavelength light. The number(More)
We report an optically-pumped semiconductor disk laser passively mode-locked with a semiconductor saturable-absorber mirror. Both the absorber and the gain media were made of dilute nitride compound semiconductor, GaInNAs, which enables operation around 1.2 microm wavelengths. The laser generated 5 ps optical pulses with an average output power up to 275(More)
The pulse evolution in Bi-doped soliton fiber laser with slow and fast saturable absorber has been studied both experimentally and numerically. Semiconductor saturable absorbers with balanced slow and fast absorption recovery mechanisms exhibit a bi-temporal recovery dynamics which permits both reliable start-up of passive mode-locking and short pulse(More)
We demonstrate for the first time the operation of GaInNAs and GaAs n-i-p-i doping solar cells with ion-implanted selective contacts. Multiple layers of alternate doping are grown by molecular beam epitaxy to form the n-i-p-i structure. After growth, vertical selective contacts are fabricated by Mg and Si ion implantation, followed by rapid thermal(More)
We report power scaling experiments of a GaInNAs/GaAs-based semiconductor disk laser operating at ~1180 nm. Using a single gain chip cooled to mount temperature of ~10 °C we obtained 11 W of output power. For efficient thermal management we used a water-cooled microchannel mount and an intracavity diamond heat spreader. Laser performance was studied using(More)