High Peak Power Pulse Amplification in Large-Core Yb-Doped Fiber Amplifiers

Spatio-Temporal Self-Focusing in Femtosecond Pulse Transmission Through Multimode Optical Fibers

“…The critical self-focusing power is given as = 1.86 4 ⁄ [1], where is the wavelength, the linear refractive index and the nonlinear index coefficient. For fused silica, ~4.6 MW at = 1.06μm, which is comparable to the peak powers of ultrashort pulses that can be obtained using Yb doped fiber amplifiers [2]. Powers above are used in manufacturing, for example, to write permanent modifications to the refractive index of multimode fibers [3].…”

Multimode Nonlinear Fibre Optics: Theory and Applications

“…In this section we will discuss these effects within the framework of the MM-NLSE, which leads to an easy understanding of fibre-based self-focusing within a modal picture Milosevic et al, 2000). Such an interpretation is particularly useful in the context of high-power fibre lasers, which now achieve peak powers close to the critical power with pulse lengths approaching the nanosecond regime (Galvanauskas et al, 2007).…”

“…The corresponding increase in accessible transmission length simultaneously started the interest in nonlinear fibre optics, for example with early work on the stimulated Raman effect (Stolen et al, 1972) and on optical solitons (Hasegawa & Tappert, 1973). Since the advent of fibre amplifiers (Mears et al, 1987), available fibre-coupled laser powers have been increasing dramatically and, in particular, fibre lasers now exceed kW levels in continuous wave (cw) operation (Jeong et al, 2004) and MW peak powers for pulses (Galvanauskas et al, 2007) in all-fibre systems. These developments are pushing the limits of current fibre technology, demanding fibres with larger mode areas and higher damage threshold.…”

High-energy 100-ns single-frequency all-fiber laser at 1064 nm

“…An average power of 913 W has been obtained on multi-stage cascaded power amplification under the high repetition rate of 10 MHz and short pulse duration of 3 ns, while the corresponding peak power was around 28.6 kW [12]. To achieve high energy singlefrequency pulses amplification for long pulse duration, many techniques have been proposed to increase the threshold of SBS, such as shortening the length and increasing the mode area of active fiber, temperature and strain gradients, and acoustically tailored active PCF [13][14][15]. Employing the strain gradient on the active fiber in power scaling stage, Chen et al achieved a single-pulse energy of ~260 µJ in a single-frequency pulsed Yb-doped MOPA configuration, where the SBS free peak power was successfully increased from 330 to 508 W [16].…”