Frequency-Tunable Two-Colour Ultrafast Fiber Laser for Nonlinear Microscopy in the Fingerprint Regime Emitting at Central Frequencies 780 nm and 810 nm to 950 nm

Summary form only given. Several nonlinear microscopy and spectroscopy techniques like SHG, THG, SRS and CARS benefit from pulsed laser systems with tunable central frequency allowing selective excitation of energy levels [1-4]. We present a fiber laser based pulsed two-arm laser system which is compact, robust, cost-effective and fully automated with regard to the adjustment of the central frequency. Both arms are seeded by the same fiber oscillator at a repetition rate of 80 MHz and can be temporally overlapped by an internal 500 ps delay. One arm is based on the TOPTICA FemtoFiber ultra 780 and emits pulses at a central frequency of 780 nm with a pulse duration of around 1 ps (FWHM) and an average power of 500 mW.