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High-power slab-based Tm:YLF laser for in-band pumping of Ho:YAG

By Sik So, Jacob I. Mackenzie, David P. Shepherd and William A. Clarkson

Abstract

Several remote sensing applications require pulsed sources in the mid-infrared spectral regime with high average powers and good beam quality. Ho:YAG lasers have a number of attractive features for high power generation at 2.1 microns, either for direct applications or as a pump source for parametric conversion to longer infra-red wavelengths. Unfortunately, direct diode pumping of Ho:YAG is not practical, so a two-step process is generally employed in which one or more diode-pumped thulium-doped lasers are used to directly pump (in-band) the Ho:YAG laser. In response, we have investigated a slab-based architecture for scaling the output power of a Tm:YLF laser to the 100W power regime at 1.91microns, corresponding to a strong Ho:YAG absorption line. Multiple slab lasers with moderate beam quality in the plane of the slab can be combined to efficiently end-pump a low-doping concentration Ho:YAG rod in a pump-guided configuration. In a preliminary demonstration, two 2at.% doped Tm:YLF slab lasers with a spatially multiplexed output of 74W were employed to end-pump a 1.5mm diameter, 80mm long, 0.25at.% Ho:YAG barrel-polished rod. A two mirror plano-concave cavity, with 11% output coupling transmission, produced a CW output of 38W with a slope efficiency of 60% with respect to the incident power. Q-switched operation at a repetition rate of 20Hz with two intracavity Brewster plate polarizers and a 60% transmitting output coupler produced 14mJ pulses with a pulse duration (FWHM) of 18ns. This architecture offers an attractive route for future high-power 2micron lasers

Topics: QC, TK
OAI identifier: oai:eprints.soton.ac.uk:50693
Provided by: e-Prints Soton

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Citations

  1. (2006). A power-scaling strategy for longitudinally diode-pumped Tm:YLF lasers,"
  2. (2007). Application and development of high-power and highly efficient silica-based fiber lasers operating at 2 mm,"
  3. (2007). Brightness-scaling potential of actively phase-locked solid-state laser arrays,"
  4. (2005). Efficient, high power, Q-switched Nd:YLF slab laser end-pumped by diode stack,"
  5. (2000). High-power dual-rod Yb : YAG laser,"
  6. (2006). High-power widely tunable Tm: fibre lasers pumped by an Er, Yb co-doped fibre laser at 1.6 mm,"
  7. (2000). High-power/high-brightness diode-pumped 1.9mm Thulium and resonantly pumped 2.1-mu m Holmium lasers,"
  8. (2003). Ho:Ho upconversion: applications to Ho lasers,"
  9. (2003). Ho:YAG laser intracavity pumped by a diode-pumped Tm:YLF laser,"
  10. (1996). Modeling of laser-pumped Tm and Ho lasers accounting for upconversion and ground-state depletion,"
  11. (2007). Review of multipass slab laser systems,"
  12. (2004). Spectroscopy and modeling of solid state lanthanide lasers: Application to trivalent Tm 3+ and Ho 3+ in YLiF4 and LuLiF4,"
  13. (1984). The Slab Geometry Laser .1. Theory,"

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