Oscillation spectral range of Yb-doped fiber lasers

Abstract

Abstract:In this brief review we consider the main factors determining the oscillation spectral range of cladding-pumped ytterbium-doped fiber lasers (YDFLs) and the results obtained for lasers emitting at various wavelengths. Like erbium-doped fiber amplifiers we suggest dividing the oscillation spectral range of YDFLs into three bands, namely: convenient (C-band), short (S-band), and long (L-band). Polymer-coated double-clad fibers with the inner cladding having a size of more than 100 µm allows one to get efficient operation in the convenient range (Cband): 1060 − 1130 nm. To get an oscillation within the S-band (976 − 980 nm and 1020 − 1060 nm) it is necessary to use active fibers with a small square of the inner cladding. Heating of the active fiber gives the possibility to get lasing within the L-band λ > 1130 nm). Another way to get an emission in this spectral range is by the application of long-wave pumping by a C-band YDFL. Also, we indicate some features that require further study.

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

“…It is well known that alumino-silicate host fiber is preferable for the long wavelength generation of Yb-doped fiber [7] because of preferential cross-sections. The Yb-doped alumino-silicate fiber used in this work was fabricated in-house by modified-chemical-vapordeposition (MCVD) and the solution doping technique.…”

“…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].…”

YDFL Operating in 1150–1200-nm Spectral Domain

“…The clad-pumped YDFLs were made with a double-clad silica-based fiber consisted of two glass fibers joined in one polymer clad (GTW fiber [17,29]) and acted as a conventional double-clad fiber. One of the fibers had a Ybdoped aluminosilicate core and a silica first clad of 14 and 125 µm diameters, respectively.…”

“…Raman [11,12] or relatively newly developed Bi-doped [13,14,15,16] fiber lasers require a long fiber length and core-pumping, both considered as disadvantages for high-power lasers. 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].…”

“…Simple step-index fiber technology is already well established. Several approaches helping to expand the operating range of such Yb-doped fibers have been reported: strong cavity coupling [21,22], core-pumping in the absorption tail [17,23,24,25], active [17,25,26] and passive [27] heating of the active fiber and other techniques [28]. As a result, 10 W level of optical power has been successfully overcome.…”