Long-term Stability of Nonlinear Pulse Compression using Solid-core Large-mode-area Fibers

Long-term stability of a laser system is crucially important for applications such as ultrafast laser spectroscopy. Unfortunately, this topic received little attention in novel pulse compression schemes. Through the ultra-stable beam pointing of the 50 kHz laser system, the long-term stability of nonlinear pulse compression (NPC) was measured for up to 17 hours at different peak powers in a fiber core. The required spectral broadening was achieved in largemode- area photonic-crystal-fibers with linearly and circularly polarized light. The optimal parameters of a NPC system operating close to the fundamental limit of the critical self-focusing peak power were found. A further compression to sub-10 fs pulses in a second fiber stage is also discussed.