Abstract

High power fast wavelength sweeping fiber lasers can be used in many ways, e.g. in nonlinear imaging methods like stimulated Raman [1] and spectro-temporal laser imaging by diffractive excitation (SLIDE) two-photon microscopy [2]. In the 900 nm region fluorescent proteins especially in brain activity measurements are of high interest [3], [4]. Unfortunately, at 900 nm and 1300 nm no appropriate fiber gain media are present and other ways of achieving high peak power, like four-wave mixing (FWM), are needed [5]. This FWM approach is used here to shift the laser power of our 1064 nm master oscillator power amplifier (MOPA) fiber laser to the 1300 nm of a Fourier Domain Mode locked (FDML) laser [6], while generating a 900 nm FWM wavelength tuneable pulsed output (Figure 1, left side). With this, 2.5 kW peak power over a 54 nm span and 70 pm spectral width at 900 nm and 1.4 kW peak power over a 105 nm span at 1300 nm is possible.

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