CW PM Multiwatts Yb-Doped Fiber Laser Directly Emitting at Long Wavelength

YDFL Operating in 1150–1200-nm Spectral Domain

“…Worth to note that due to a small emission cross-section in the emission tail [26,30] the gain for ASE at the threshold is already quite high for an usual coupling of several percents. Just for demonstration, for a well inverted laser medium the gain per one way cavity trip would be about 70 dB at 1070 nm wavelength for the YDFL operated at 1160-1180 nm wavelength with a normally cleaved fiber end as an OC, what is apparently unrealistic.…”

“…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.…”

“…As a result, 10 W level of optical power has been successfully overcome. Thus, the output power of 12 W at 1178 nm was demonstrated for the core-pumped at 1090 nm YDFL [23]; actively heated up to 80 o C diode-pumped YDFL operating at the 1154 nm wavelength with 18 W of the output power was reported [26]. However, the question remains whether the further power scaling is possible and what are the factors helping or preventing it.…”

An Yb-Raman cascaded fiber laser with temporal stability

“…Taking the Yb-doped fiber laser (YDFL) as an example, high power fiber lasers have been achieved at conventional wavelength between 1030 nm and 1090 nm [1,2,6]. However, it is difficult to obtain the laser at longer wavelength beyond 1100 nm where gain is low and competition with amplified spontaneous emission (ASE) is a severe problem [2,7,8] RFLs. Due to the instantaneous nature of SRS, the temporal character of the RFL is determined by that of the pump fiber lasers [12], so the self-pulsation can appear in the RFL.…”

High power ytterbium fiber lasers at extremely long wavelengths by photonic bandgap fiber technology

“…Yb 3+ -doped fiber lasers operating at the long-wavelength edge (1150-1200 nm) of the fluorescence have been investigated [9][10][11][12][13][14][15]. They have advantageous features such as laser-diode (LD) direct pumping, mild nonlinearity, and thus simple architectures.…”