A triple cladding fiber for pulse stretching

There is a high demand for fiber-based sources of high-peak and high-energy pulses in many fields, e.g. micro machining. A classical approach to generate such pulses is the chirped pulse amplification (CPA) method, where pulses consequently propagates through a stretching stage, an amplification stage, and a compression stage. The stretching stage prior the amplification stage is required to decrease the pulse intensity, and thereby to reduce a detrimental impact of the nonlinear effects (such as stimulated Raman scattering, self-phase modulation) on pulse. As the stretching stage one can use any device this normal dispersion, but using a fiber is preferably to keep the stretching system compact, alignment-free and cheap. By changing a fiber design, its dispersion parameter and third to second order dispersion ratio can be tailored to match the compressor stage dispersion and ensure a good compression efficiency of amplified pulses.