Tu Y, Jauregui C, Kholaif SE, Limpert J (2022)
Publication Type: Conference contribution
Publication year: 2022
Publisher: SPIE
Book Volume: 11981
Conference Proceedings Title: Proceedings of SPIE - The International Society for Optical Engineering
Event location: Virtual, Online
ISBN: 9781510648333
DOI: 10.1117/12.2609322
Modal decomposition (MD) techniques are a way to characterize the modal amplitudes and phases of eigenmodes in optical fibers. Some applications such as, e.g., diagnosing/analyzing transverse mode instabilities or monitoring a laser beam during operation, require a high-speed modal decomposition. However, the proposed modal decomposition techniques up to now are seldom able to implement a real-time MD due to their complex post-processing (e.g., most of the numerical computing-based MD). In this work a high-speed, real-time modal decomposition of fiber laser beams is presented. It employs a spatial mode multiplexer (MUX), which is a multipass cavity with multiple single-mode fiber (SMF) inputs and a single few-mode fiber (FMF) output, operated in reverse. Thus, if the output of a fiber laser system is imaged on the end facet of the FMF, then the MUX is used as a demultiplexer and, thus, the modal amplitude information can be obtained by reading out the different SMF input ports. We have carried out several experiments with the MUX and it has been proven that this method is accurate and extremely fast. In fact, it is even able to decompose the beam during a Q-switched pulse emission and produce real-time results.
APA:
Tu, Y., Jauregui, C., Kholaif, S.E., & Limpert, J. (2022). Real-time modal decomposition of fiber laser beams using a spatial mode multiplexer. In Cesar Jauregui-Misas, V. R. Supradeepa (Eds.), Proceedings of SPIE - The International Society for Optical Engineering. Virtual, Online: SPIE.
MLA:
Tu, Yiming, et al. "Real-time modal decomposition of fiber laser beams using a spatial mode multiplexer." Proceedings of the Fiber Lasers XIX: Technology and Systems 2022, Virtual, Online Ed. Cesar Jauregui-Misas, V. R. Supradeepa, SPIE, 2022.
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