Fiber components based on large-mode area chirally coupled core specialty fibers for all-fiber laser systems

authored by: Eike Brockmüller, Felix Wellmann, Ossi Kimmelma, Tyson Lowder, Steffen Novotny, Jörg Neumann, Dietmar Kracht
Abstract: Fiber-based laser systems enable high output power in combination with diffraction limited beam quality. Their output power is generally limited by the onset of nonlinear effects. The chirally coupled core (CCC) fiber provides a large mode field diameter while also suppressing higher-order-modes. This is needed to further increase a laser’s output power and maintaining single-mode operation. However, the integration of specialty fibers in an all-fiber laser setup is in most cases not possible because suitable fiber components are not available. We report on the development of a cladding light stripper and a signal-pump combiner with integrated 34/250-µm CCC fibers which allow for the development of spliceless all-fiber amplifier systems. The cladding light stripper is manufactured by structuring the CCC-fiber’s cladding using a CO₂-laser to interrupt pump light guiding within the cladding. The cladding light stripper enables a stripping efficiency of 19 dB and was tested up to a stripped optical power of 100 W, which is sufficient to enable kW-class amplifier systems. The signal-pump combiner relies on a side-pumped design with four pump input fibers. Its characterization reveals a pump-to-signal fiber coupling efficiency of 90% and a signal-to-pump isolation of 30 dB. Component stability was tested at a pump input power of 500 W. An S²-measurement confirmed that the spatial mode content of the signal light propagating through the CCC-fiber-based signal-pump combiner remains unaffected. Furthermore, a signal-pump combiner was subjected to temperature cycles between -5 and 85 °C over a time period of >1000 h and showed no degradation.
Organisation(s): QuantumFrontiers
External Organisation(s): Laser Zentrum Hannover e.V. (LZH)
nLIGHT Corporation, Lohja
nLIGHT
Type: Conference contribution
Publication date: 30.05.2023
Publication status: E-pub ahead of print
Peer reviewed: Yes
ASJC Scopus subject areas: Electronic, Optical and Magnetic Materials, Condensed Matter Physics, Computer Science Applications, Applied Mathematics, Electrical and Electronic Engineering
Electronic version(s): https://doi.org/10.1117/12.2665663 (Access: Closed)

BibTeX

@inproceedings{9dc889ce515b495fa58dd142b815a155,
title = "Fiber components based on large-mode area chirally coupled core specialty fibers for all-fiber laser systems",
abstract = "Fiber-based laser systems enable high output power in combination with diffraction limited beam quality. Their output power is generally limited by the onset of nonlinear effects. The chirally coupled core (CCC) fiber provides a large mode field diameter while also suppressing higher-order-modes. This is needed to further increase a laser{\textquoteright}s output power and maintaining single-mode operation. However, the integration of specialty fibers in an all-fiber laser setup is in most cases not possible because suitable fiber components are not available. We report on the development of a cladding light stripper and a signal-pump combiner with integrated 34/250-µm CCC fibers which allow for the development of spliceless all-fiber amplifier systems. The cladding light stripper is manufactured by structuring the CCC-fiber{\textquoteright}s cladding using a CO2-laser to interrupt pump light guiding within the cladding. The cladding light stripper enables a stripping efficiency of 19 dB and was tested up to a stripped optical power of 100 W, which is sufficient to enable kW-class amplifier systems. The signal-pump combiner relies on a side-pumped design with four pump input fibers. Its characterization reveals a pump-to-signal fiber coupling efficiency of 90% and a signal-to-pump isolation of 30 dB. Component stability was tested at a pump input power of 500 W. An S2-measurement confirmed that the spatial mode content of the signal light propagating through the CCC-fiber-based signal-pump combiner remains unaffected. Furthermore, a signal-pump combiner was subjected to temperature cycles between -5 and 85 °C over a time period of >1000 h and showed no degradation.",
keywords = "chirally coupled core, Fiber components, laser amplifier, signal-pump combiner, specialty fiber",
author = "Eike Brockm{\"u}ller and Felix Wellmann and Ossi Kimmelma and Tyson Lowder and Steffen Novotny and J{\"o}rg Neumann and Dietmar Kracht",
note = "Publisher Copyright: {\textcopyright} 2023 SPIE.; Specialty Optical Fibres 2023 ; Conference date: 24-04-2023 Through 28-04-2023",
year = "2023",
month = may,
day = "30",
doi = "10.1117/12.2665663",
language = "English",
series = "Proceedings of SPIE - The International Society for Optical Engineering",
publisher = "SPIE",
editor = "Kyriacos Kalli and Alexis Mendez and Pavel Peterka",
booktitle = "Specialty Optical Fibres",
address = "United States",
}