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Photostimulation by Femtosecond Laser Activates Extracellular-signal-regulated Kinase ERK Signaling or Mitochondrial Events in Target Cells
Published on: July 6, 2019
Femtosecond-laser-written Ho:KGd(WO4)2 waveguide laser at 2.1 μm
Abstract:
We report on efficient laser operation of the first holmium monoclinic double tungstate waveguide laser fabricated by femtosecond direct laser writing. A depressed-index buried channel waveguide with a 60 μm diameter circular cladding was inscribed in 5 at.% Ho3+:KGd(WO4)2. It was characterized by confocal microscopy and μ-Raman and μ-luminescence spectroscopy, indicating well-preserved crystallinity of its core. Pumped by a thulium bulk laser, the holmium waveguide laser generated 212 mW at 2055 nm with a slope efficiency of 67.2%. The waveguide propagation losses were 0.94±0.2 dB/cm.
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