Showing papers by "Alexander J. Boyland published in 2008"
TL;DR: High-power operation of a fiber distributed-feedback (DFB) laser fabricated from Tm-doped photosensitive alumino-silicate fiber and in-band pumped by an Er/Yb fiber laser at 1565 nm is reported.
Abstract: We report on high-power operation of a fiber distributed-feedback (DFB) laser fabricated from Tm-doped photosensitive alumino-silicate fiber and in-band pumped by an Er/Yb fiber laser at 1565 nm. The fiber DFB laser yielded up to 875 mW of single-ended output at 1943 nm on two orthogonally polarized modes for 3.5 W of absorbed pump power. Further scaling of the DFB laser output power was achieved with the aid of a simple Tm-doped fiber amplifier stage spliced directly to the DFB fiber without the need of an optical isolator. The maximum output power from the DFB laser and fiber amplifier was >3 W for a combined absorbed pump power of 8.1 W. The influence of thermal loading, owing to quantum defect heating in the Tm-doped core, on the output power and longitudinal mode behavior is discussed, and the prospects for further improvement in performance are considered.
65 citations
TL;DR: The photodarkening of Yb-doped aluminosilicate fibers by continuous wave 488 nm irradiation could be significantly reduced, which is attributed to a smaller number of ODCs following oxygen loading.
Abstract: In response to the Comment, we show that Engholm et al. [Opt. Lett. 33, 1216 (2008)] misinterpret the absorption peak at 230 nm and reach mistaken conclusions that contradict their experimental results. Differences in compositions and fabrication details mean that their results are only marginally relevant to our experiments [Opt. Lett. 32, 1626 (2007)]. The excitation of electrons to a charge-transfer band around 230 nm in Yb-doped aluminosilicate glasses leads to conversion from Yb, which, in our opinion, is more likely to account for photobleaching rather than photodarkening.
35 citations
TL;DR: A narrow-linewidth mid-IR source based on difference-frequency generation of an amplified 1.5 microm diode laser and a cw Tm-doped fiber laser in orientation-patterned (OP) GaAs has been developed and evaluated for spectroscopic applications.
Abstract: A narrow-linewidth mid-IR source based on difference-frequency generation of an amplified 1.5µm diode laser and a cw Tm-doped fiber laser in orientation-patterned (OP) GaAs has been developed and evaluated for spectroscopic applications. The source can be tuned to any frequency in the 7.6-8.2µm range with an output power of 0.5mW. The measured characteristics of the OP-GaAs sample demonstrate a high quality of the material.
29 citations
04 May 2008
TL;DR: In this article, photodarkening in highly Yb-doped aluminosilicate and phosphosilicates fibers, under 488 nm irradiation, is presented.
Abstract: Photodarkening in highly Yb-doped aluminosilicate and phosphosilicate fibers, under 488 nm irradiation, is presented. Both irradiation-induced excess loss and post-irradiation temporal loss evaluations reveal that Yb-doped phosphosilicate fiber is highly resistant to photodarkening.
20 citations
04 May 2008
TL;DR: In this article, the authors report efficient operation of a narrow-linewidth master-oscillator power-amplifier (MOPA), based on a Tm-doped fiber distributed-feedback laser and two amplifier stages, in-band pumped at 1565 nm.
Abstract: We report efficient operation of a narrow-linewidth master-oscillator power-amplifier (MOPA), based on a Tm-doped fiber distributed-feedback laser and two amplifier stages, in-band pumped at 1565 nm. The MOPA yielded 10 W of linearly-polarized single-frequency output at 1943 nm.
4 citations
01 Dec 2008
TL;DR: In this paper, the progress in rare-earth doped fiber technology towards power scaling of high-brightness fiber sources is reviewed, with a focus on the power scaling problem.
Abstract: This paper reviews the progress in rare-earth doped fibre technology towards power scaling of high-brightness fibre sources.
1 citations