High brightness in-band pumped fiber MOPA with output power scaling to >4.6 kW


Mete B., Yeniay A., Ecevit F. N., Kalyoncu S. K.

Applied Optics, vol.61, no.34, pp.10121-10125, 2022 (SCI-Expanded) identifier identifier identifier

  • Publication Type: Article / Article
  • Volume: 61 Issue: 34
  • Publication Date: 2022
  • Doi Number: 10.1364/ao.479366
  • Journal Name: Applied Optics
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus, Aerospace Database, Applied Science & Technology Source, Aquatic Science & Fisheries Abstracts (ASFA), Communication Abstracts, Compendex, EMBASE, MEDLINE, DIALNET
  • Page Numbers: pp.10121-10125
  • Kocaeli University Affiliated: No

Abstract

© 2022 Optica Publishing Group.An in-band pumping technique that employs low numerical aperture (NA) and high brightness fiber lasers emitting at 1018 nm enables outstanding power scaling performance by increasing pump power handling capacity of fiber components, reducing thermal load and quantum defect. Here, we present design criteria for an in-band pumped fiber master oscillator power amplifier (MOPA) structure, pumped with 1018 nm fiber lasers, as well as mitigation strategies for nonlinear effects for scalable single-mode laser operation at multi-kilowatt power levels. In addition, we report experimental demonstration of an in-band pumped MOPA with an output power scaling up to 4.63 kW and a slope efficiency of ∼88%. The MOPA system is pumped by 18× 264 W high brightness fiber lasers operating at 1017.8 ± 0.3 nm with an NA of <0.075. The laser emits at 1080.4 nm wavelength with a stimulated Raman scattering suppression of >36.8 dB and has a near-diffraction-limited beam quality of M2 ∼ 1.61. To the best of our knowledge, our laser has the highest brightness of 153 GW · cm−2 · sr−1 reported at 1080 nm in co-pumping configuration.