Oscillation spectral range of Yb-doped fiber lasers

TLDR

Ytterbium‑doped fiber lasers can be categorized into convenient (C‑band 1060–1130 nm), short (S‑band 976–980 nm and 1020–1060 nm), and long (L‑band >1130 nm) spectral ranges, with the achievable band determined by fiber geometry, cladding size, and pumping conditions. This review examines the key factors that set the oscillation spectral range of cladding‑pumped YDFLs and summarizes results for lasers operating at different wavelengths, highlighting areas for further investigation. The authors analyze how inner‑cladding size, fiber shape, heating, and long‑wave pumping influence the spectral band, drawing on experimental data from various YDFL configurations.

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 (C-band): 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.