Large Mode Area Solid-Core Photonic Bandgap Yb-Doped Fiber With Hetero-Structured Cladding for Compact High-Power Laser Systems

Spectrally U-shaped profile of beam propagation factor in all-solid photonic bandgap fiber

“…The third PBG covers broadband transmission ranging from 990 nm to 1180 nm, covering the typical operating wavelengths of high-power fiber lasers (e.g., from 1060 nm to 1090 nm). Owing to the bend-insensitive ability and potential for mode area scaling, designs of AS-PBGF in the third PBG are generally preferred in the reported works [11,17,19] . Furthermore, limited by the available light sources, the research on the modal characteristics of AS-PBGF concentrates on the third PBG in this work.…”

“…Large-mode-area (LMA) fibers working with advanced mechanisms have been established as promising candidates for next-generation high-power fiber lasers, benefitting from their potentials in mode area scaling, higher nonlinear threshold, and feasibilities for some functional applications [1][2][3][4][5][6] . More recently, a kind of bandgap-guided microstructure fiber, called the allsolid photonic bandgap fiber (AS-PBGF), has become an emerging research focus [7][8][9][10][11][12] . Free of air-holes structures, AS-PBGF exhibits excellent practical convenience for the high-power platform [13] and portability for the double-cladding design or polarization-maintaining scheme [11] .…”

“…More recently, a kind of bandgap-guided microstructure fiber, called the allsolid photonic bandgap fiber (AS-PBGF), has become an emerging research focus [7][8][9][10][11][12] . Free of air-holes structures, AS-PBGF exhibits excellent practical convenience for the high-power platform [13] and portability for the double-cladding design or polarization-maintaining scheme [11] . The all-solid structure ensures the ease of cleaving and splicing, making a compact all-fiber configuration possible.…”

“…Robust single-mode (SM) operation with high loss ratio between the fundamental mode (FM) and high-order modes (HOMs) is achievable due to the opencladding of AS-PBGF [7] . By combining the stack-and-draw method with rare-earth doping technology, the production of active AS-PBGF has gradually become an internal technology mastered by only a few organizations [8,9,11,12,14,15] . Over kilowatt-level emission by using double-cladding active AS-PBGF has been successfully demonstrated [16] .…”

High‐Power Laser Systems

“…Nonetheless, the increased difficulty and complexity of fabrication caused by noncircular fiber symmetry and additional codoping to eliminate index mismatching delay their practical applications. [368] The [77,431,433,434,437,[439][440][441][442][443]445,446,448,449,455,459,460,464,470,[472][473][474][475][476][477][478][479][480] classic fibers used in high-power lasers are mainly rod-type PCFs, leakage channel PCFs (LC-PCFs), and large pitch PCFs (LPFs). Their characteristics and functions will be further described next.…”