Ultrafast fiber lasers represent an affordable source for performing non-linear spectroscopies, like transient absorption or coherent antistokes Raman scattering, and can advance these technologies towards commercial devices. We experimentally investigate the generation of white light in photonic crystal fibers at low pulse energies and high repetition rates using 775 nm pulses at 80 MHz from the second harmonic of an Er:fiber laser. Two different fibers were chosen based on non-linear beam-propagation simulations. The generated broadband light was characterized and compared in terms of spectral bandwidth, pulse duration and shot-to shot noise, showing good agreement with the simulations.

We present a transient absorption setup based on a low-power laser system and a photonic crystal fiber for supercontinuum generation. The setup employs an ultrafast erbium-doped fiber laser system that emits at 775 nm with 80 MHz repetition rate which pumps a non-linear photonic crystal fiber that provides a supercontinuum in the NIR/VIS wavelength region for probing. By using an acousto optic modulator for pump-beam modulation and a lock-in amplifier we were able to achieve a detection-limit of 1 µOD. The setup reveals the potential of photonic crystal fibers as broadband sources in combination with low-power lasers.