Abstract Recent years have witnessed significant advancements in hollow-core fiber gas lasers (HCFGLs), driven by developments in hollow-core fiber (HCF) design and fabrication. These novel lasers are characterized by hollow-core structure, providing an ultralong and tiny interaction region for light and gases, thereby enabling light amplification with high efficiency, high beam quality, and tunability. HCFGLs has achieved broadband emission spanning from ultraviolet to mid-infrared (MIR) region, with a record output wavelength exceeding 4.8 μm in silica-based fiber lasers. Output power has surpassed 100 W in the near-infrared and reached an impressive 21.8 W in the MIR region. With the continuing reduction of attenuation in HCFs, particularly in the MIR regime, HCFGLs holds promises for potential applications in trace gas detection, space communication, polymer processing, medical treatment, national defense, etc. In this review, we focus on the basic principles and research progress of HCFGLs. The paradigm shifts history of HCFs are reviewed first. The development history and representative works of HCFGL based on the population inversion and stimulated Raman scattering are then introduced in detail. Finally, the future trends toward power enhancement, spectral expansion, and practical applications are also outlined. We hope this review will provide valuable insights for HCFGL researchers and interested readers, while also offering potential pathways to achieve otherwise challenging laser wavelength outputs and further power scaling.
Wang et al. (Mon,) studied this question.