Cladding-Pumped Yb-Doped Solid Photonic Bandgap Fiber for ASE Suppression in Shorter Wavelength Region

Multi-watts narrow-linewidth all fiber Yb-doped laser operating at 1179 nm

“…Different approaches have been proposed to operate Yb-doped fiber lasers in the long wavelength (1160-1180 nm) range [4][5][6][7][8][9][10][11]. Because the emission cross-section of Yb-doped aluminosilicate fibre extends up to 1200 nm, using conventional Yb-doped fiber, an output of 121 mW at 1150 nm was achieved with a slope efficiency of 21%, by pumping at 977 nm [4].…”

“…The maximum slope efficiency, with respect to pump power was 45% at 1160 nm, with a maximum output power of 3.3 W. However, the low emission cross section at these wavelengths and the gain competition from shorter wavelengths, especially in the 1030-1100 nm wavelength range, leads to the generation of amplified spontaneous emission (ASE) and parasitic lasing at high pump power limiting the utilizable gain and power scaling, making the operation a challenging work. Other alternatives have been proposed to overcome those issues, such as a cladding pumped Yb-doped solid photonic bandgap fibers for suppression of ASE at 1030 nm [8]. Also, by using the spectral filtering properties of photonic bandgap fibers, with a Raman fiber laser seeded MOPA configuration, 32 W output at 1156 nm and 30 W output at 1178 nm has been realized [10].…”

Simple analysis of water-filled hollow-core silica photonic bandgap fiber

“…First, we investigate PBF with high refractive index fillings, as all-solid PBFs [5,6,7] and liquid crystal PBFs have already been reported. [3,4] Liquid crystals or flint glass [13] are candidates as high index materials for filling the cladding holes.…”

“…Solid silica based PBF is being studied with a view to realizing high power fiber lasers by employing the filtering effect of the PBF [5,6]. The cladding of this type of PBF consists of an alignment of high index rods.…”

YDFL Operating in 1150–1200-nm Spectral Domain

“…The main problem in establishing such YDFLs is athe high ASE level and athe parasitic lasing at shorter wavelengths [17]. Special fiber design when the ASE is naturally filtered by the fiber improves the situation [18], resulting in 167 W of output power at 1178 nm, achieved in Yb-doped specialty photonic bandgap fiber amplifier with 5 W seed power [19]. However, the output powers of such fiber lasers without amplification are sufficiently lower.…”