Chinese Optics, Volume. 17, Issue 1, 226(2024)
Stimulated brillouin scattering in double-clad thulium-doped fiber amplifier
Fig. 1. Structure and refractive index distribution of DTDF-10/130 double-clad thulium-doped fiber
Fig. 2. Structure and refractive index distribution of DTDF-25/400 double-clad thulium-doped fiber
Fig. 3. Schematic diagrams of the (a) two-dimensional and (b) three-dimensional optical field distributions of the LP01 mode of the DTDF-10/130 double-clad thulium-doped fiber at 2 μm wavelength, respectively
Fig. 4. Optical field distribution of DTDF-25/400 double-clad thulium-doped fiber at 2 µm wavelength. (a)−(c) Schematic diagrams of the two-dimensional optical field distributions for LP01, LP11 (o) and LP11 (e); (d)−(f) schematic diagrams of three-dimensional optical field distributions for LP01, LP11 (o) and LP11 (e)
Fig. 5. Schematic diagram of the normalized frequency with signal wave wavelength for DTDF-10/130 and DTDF-25/400 double-clad thulium-doped fibers
Fig. 6. Effective refractive index and effective mode field area of different optical wave modes in two fibers in the 1.9~2.1 µm band. (a) LP01 mode in DTDF-10/130 double-clad thulium-doped fiber; (b) LP01 and LP11 modes in DTDF-25/400 double-clad thulium-doped fiber
Fig. 7. Variation of power filling factor with wavelength in double-clad thulium-doped fibers DTDF-10/130 and DTDF-25/400
Fig. 8. Optical wave modes of 793 nm pump wave in different fibers. (a)-(d) DTDF-10/130; (e)-(h) DTDF-25/400 double-clad thulium-doped fiber
Fig. 9. Optical modes corresponding to small power filling factor in the inner cladding at a wavelength of 793 nm for the pump wave
Fig. 10. Schematic diagram of intra- and inter-mode Brillouin scattering of different optical wave modes in two fibers operating at 1.9~2.1 µm laser wavelengths
Fig. 11. LP01-LP01 intra-mode Brillouin gain coefficient in DTDF-10/130 double-clad thulium-doped fiber, LP01-LP01 intra-mode, LP11-LP11 intra-mode and LP01-LP11 inter-mode Brillouin gain coefficients in DTDF-25/400 double-clad thulium-doped fiber at the 1.9~2.1 µm laser waveband
Fig. 12. Brillouin gain spectra at laser wavelength of 2 µm. (a) Brillouin scattering within LP01-LP01 mode in DTDF-10/130 double-clad thulium-doped fiber; (b) Brillouin scattering within LP01-LP01 mode, LP11-LP11 mode and LP01-LP11 inter-mode in DTDF-25/400 double-clad thulium-doped fiber
Fig. 13. Distribution of pump wave power, signal wave power and Stokes wave power along the fiber
Fig. 14. Residual pumping optical powers varying with fiber length at different pump optical power filling factors
Fig. 15. Variation of laser output power and Stokes optical power with fiber length when pump power filling factors are (a) 0.01, (b) 0.02, and (c) 0.03, respectively
Table 1. Geometry and optical properties of double-clad thulium-doped fibers
View tableView in ArticleTable 1. Geometry and optical properties of double-clad thulium-doped fibers
Properties Unit DTDF-10/130 DTDF-25/400 Core diameter µm 10.0 ± 1.0 25.0 ± 2.5 Diameter of inner cladding µm 130.0 ± 3.0 400.0 ± 15.0 Concentricity error of core/internal cladding µm ≤ 2.0 ≤ 4.0 Diameter of coating layer µm 215.0 ± 10.0 550.0 ± 20 Operating wavelength nm 1900 ~ 2100 1900 ~ 2100 Core numerical aperture —— 0.150 ± 0.010 0.090 ± 0.010 Numerical aperture of inner cladding —— ≥ 0.460 ≥ 0.460
Table 2. Simulation parameters of thulium-doped fiber amplifier
View tableView in ArticleTable 2. Simulation parameters of thulium-doped fiber amplifier
Parameter Symbol Value Unit Fiber core diameter a 10.0 µm Inner cladding diameter b 130.0 µm Tm3+ doping concentration N0 5.5×1025 m−3 Pump wavelength λp 793 nm Signal wave wavelength λs 2 µm Pump wave absorption cross section σa(λp) 8.5×10−25 m2 Pump wave emission cross section σe(λp) 8.9×10−25 m2 Signal wave absorption cross section σa(λs) 0.1×10−25 m2 Signal wave emission cross section σe(λs) 6.2×10−25 m2 Stimulated Brillouin scattering gain gB 2.803×10−11 m/W Brillouin noise ISBS 3.350×10−7 W Pumped optical fiber loss αp 1.2×10−2 m−1 Signal optical fiber loss αs 2.3×10−3 m−1 Pump optical power filling factor Γp Influenced by the shape of the inner cladding - Signal optical power filling factor Γs 0.817 -
Get Citation
Copy Citation Text
Qing-min LIU, Hui-jie SUN, Shang-lin HOU, Jing-li LEI, Gang WU, Zu-yong YAN. Stimulated brillouin scattering in double-clad thulium-doped fiber amplifier[J]. Chinese Optics, 2024, 17(1): 226
Category:
Received: May. 16, 2023
Accepted: --
Published Online: Mar. 28, 2024
The Author Email: Shang-lin HOU (houshanglin@vip.163.com)
