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摘要:
In this paper, we demonstrate the generation of a radially polarized beam (RPB) with a maximum average output power of 20 W by our self-developed nanosecond pulsed ytterbium (Yb)-doped fiber MOPA system. The method of spatial phase conversion was adopted for the system, and a liquid crystal polymer (LCP) vortex half-waveplate (LCP-WPV) was utilized to realize efficient conversion of the linearly polarized LP01 mode to the radially polarized TM01 mode. A narrow-linewidth, linearly polarized fundamental mode with an average power of 20.5 W was produced in the multistage all-fiber MOPA system consisting of a continuous-wave (CW) single-frequency fiber laser seed, an electro-optical intensity modulator, two-stage core-pumped amplifiers and three-stage cladding-pumped amplifiers. Afterwards, an RPB output with a 20 W maximum average output power, a 7.5 ns pulse width and a 10 kHz repetition rate was finally obtained after the LCP-WPV was adopted as the spatial mode converter. Then, the mode purity of the RPB was measured to be approximately 88.5 % with the PBS (polarization beam splitter) method. This work provides a reference for the generation of cylindrical vector beam sources with the advantages of high efficiency and high mode purity. © 2020 Elsevier GmbH
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来源 :
Optik
ISSN: 0030-4026
年份: 2020
卷: 224
3 . 1 0 0
JCR@2022
ESI学科: PHYSICS;
ESI高被引阀值:100