Phosphate Nd:glass materials for femtosecond pulse generation

Two different phosphate Nd-doped glasses have been investigated ill a diode-pumped femtosecond laser. To our knowledge, only Schott's phosphate glasses were previously used in fermtosecond oscillators. A slightly different behaviour was observed in our experiments, with respect to earlier reports: clean sech(2)-pulses with duration < 400 fs were routinely generated with wavelength corresponding to the fluorescence peak approximate to 1054 nm, whereas shorter pulses occurred at red-shifted wavelengths near 1067 nm. With a single 1-W pump diode (broad area emitter), cw slope efficiency as high as 32% and 139-fs pulse generation were demonstrated. (c) 2007 Elsevier B.V. All rights reserved.