A Stable Dual-wavelength Thulium-doped Fiber Laser at 1.9 μm Using Photonic Crystal Fiber.
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ABSTRACT:
SUBMITTER: Soltanian MR
PROVIDER: S-EPMC4600979 | biostudies-other | 2015
REPOSITORIES: biostudies-other
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Project description:The aim of this study was to evaluate the usefulness of a thulium-doped fiber laser and a diode laser in zero ischemia kidney surgery, by carrying out a comparative study in a pig model. Research was carried out on 12 pigs weighing 30 kg each. A thulium-doped fiber laser (TDFL) and a diode laser (DL) operating at wavelengths of 1940 and 1470 nm, respectively, were used. The cut sites were assessed both macroscopically and microscopically. The zone of thermal damage visible in the histopathological preparations was divided into superficial and total areas. During partial nephrectomy, moderate to minimal bleeding was observed, which did not require additional hemostatic measures. All animals survived the procedure. On day 0, the total thermal damage depth was 837.8 µm for the TDFL and 1175.0 µm for the DL. On day 7, the depths were 1556.2 and 2301.7 µm, respectively. On day 14, the overall thermal damage depth for the DL was the greatest (6800 µm). The width of the superficial zone was significantly reduced on days 7 and 14 after TDFL application. Both lasers are suitable for partial wedge nephrectomy without ischemia in pigs. The TDFL produced similar or better hemostasis than the DL, with a smaller zone of thermal damage and, therefore, seems more suitable for application in human medicine.
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Project description:Highly Tm(3+) doped optical fibers are urgently desirable for 2.0 μm compact single-frequency fiber laser and high-repetition-rate mode-locked fiber laser. Here, we systematically investigated the optical parameters, energy transfer processes and thermal properties of Tm(3+) doped barium gallo-germanate (BGG) glasses. Highly Tm(3+) doped BGG glass single mode (SM) fibers were fabricated by the rod-in-tube technique. The Tm(3+) doping concentration reaches 7.6 × 10(20) ions/cm(3), being the reported highest level in Tm(3+) doped BGG SM fibers. Using ultra short (1.6 cm) as-drawn highly Tm(3+) doped BGG SM fiber, a single-frequency fiber laser at 1.95 μm has been demonstrated with a maximum output power of 35 mW when in-band pumped by a home-made 1568 nm fiber laser. Additionally, a multilongitudinal-mode fiber laser at 1.95 μm has also been achieved in a 10 cm long as-drawn active fiber, yielding a maximum laser output power of 165 mW and a slope efficiency of 17%. The results confirm that the as-drawn highly Tm(3+) doped BGG SM fibers are promising in applications that require high gain and high power from a short piece of active optical fiber.
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Project description:IntroductionSeveral modalities are used to improve the outcome of liver resection surgery. Laser-based surgery may become promising option; therefore we aim to report our experience regarding the efficacy and safety of Thulium-Doped Fiber Laser (TDFL) 1940 nm in liver parenchyma resection.MethodsA cross sectional study in which patients with pre-existing liver pathology during July 2019 and July 2020 were randomly assigned to receive liver resection using TDFL integrated with raman laser emitting at 1940 nm and 1470 nm wavelength. Data on estimated blood loss during liver transection, liver transection speed, morbidity rate, and postoperative variables including complications, length of hospital stay (days), and mortality were analyzed.ResultsA total of 17 consecutive liver resections were performed, among them are 7 major and 11 minor hepatectomies. The Multipulse TM+1470 were used on 8 procedures consisted of 1 major and 7 minor hepatectomies, the mean amount of blood loss during operation and liver transection was 628.13 ± 141.31 mL and 294.63 ± 94.81 ml, respectively. The mean liver transection speed was 1.52 ± 0.27 cm2/min. No biliary leak, post-hepatectomy-liver failure, and mortality were reported.ConclusionTDFL provided by Multipulse TM+1470 is an effective and safe tool for liver surgery, providing good hemostasis and allowing for safe and effective exposure of vascular. Further study with larger samples might be needed proved the efficacy and safety of TDFL in liver surgery.
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