Presentation
13 March 2019 Generation and amplification of a LG01 laser with a thermally-guiding fiber-rod (Conference Presentation)
Author Affiliations +
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.
Conference Presentation
© (2019) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Thomas L. Jefferson-Brain, Qiyao Liu, Peter C. Shardlow, and William A. Clarkson "Generation and amplification of a LG01 laser with a thermally-guiding fiber-rod (Conference Presentation)", Proc. SPIE 10896, Solid State Lasers XXVIII: Technology and Devices, 108961A (13 March 2019); https://doi.org/10.1117/12.2511648
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KEYWORDS
High power fiber amplifiers

Neodymium lasers

Optical amplifiers

Diodes

Fiber amplifiers

Fiber coupled lasers

High power lasers

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