Jefferson-Brain, T.L., Liu, Q., Shardlow, P.C. and Clarkson, W.A. (2019) Generation and amplification of a LG01 laser with a thermally-guiding fiber-rod. In Solid State Lasers XXVIII: Technology and Devices. SPIE..
Abstract
Laguerre-Gaussian (LG) modes have properties that make them well suited to many applications, particularly laser processing when scaled to high-power. Here we present an approach for generating high-purity LG01 vortex beams in a Nd:YVO4 laser which overcomes the common problems of degenerate handedness and low damage thresholds in previous methods. The obtained modes are scaled in power by application of a novel Thermally-Guiding Fiber-Rod Amplifier (TGFRA).
Our approach is based on a novel end-pumping arrangement for efficiently generating the Hermite-Gaussian TEM01 mode in a 1064 nm Nd:YVO4 laser. A fiber-coupled laser diode was spliced to a 50:50 fiber splitter to give two equal outputs. These outputs were bonded to a bulk optic with a small separation for spatially matching the TEM01 mode. An astigmatic mode converter made using two concave mirrors was used to obtain a LG01 mode with controlled handedness.
The obtained LG01 mode was propagated through the 300 µm core of a 10 cm long sample of triple-clad Yb-doped silica fiber by utilizing thermal lensing as a waveguiding mechanism. The fiber was pumped using a high-power 915 nm diode laser. This amplifier geometry ensures preservation of the mode while the inheriting good thermal management from a fiber geometry and the large mode area common in rod geometries.
The 0.89 W LG01 seed-source was amplified with gain of 2.7 dB. The gain was limited by available pump power and the emission cross-section at 1064 nm. This result provides an avenue to high-power LG01 modes.
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- Current Faculties > Faculty of Engineering and Physical Sciences > Zepler Institute for Photonics and Nanoelectronics > Fibre and Systems Group
Zepler Institute for Photonics and Nanoelectronics > Fibre and Systems Group - Faculties (pre 2018 reorg) > Faculty of Physical Sciences and Engineering (pre 2018 reorg) > Optoelectronics Research Centre (pre 2018 reorg)
Current Faculties > Faculty of Engineering and Physical Sciences > Zepler Institute for Photonics and Nanoelectronics > Optoelectronics Research Centre (pre 2018 reorg)
Zepler Institute for Photonics and Nanoelectronics > Optoelectronics Research Centre (pre 2018 reorg)
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