Passively Mode-Locked Self-Frequency Doubling Yb:LGSB Laser

Non-centrosymmetric crystals exploited as host matrices for rare earth active ions simultaneously enable a self-frequency doubling (SFD) process. In case of ytterbium doping it allows to obtain laser radiation at 1 μm and its SFD signal covering green spectral range. This mechanism is particularly interesting in case of mode-locked oscillators as the intensity within the crystal is much higher, thus increasing the conversion efficiency. Moreover, it can be also employed for cascaded χ
⁽²⁾
processes. Nevertheless, despite more than 20 years of development of Yb-doped mode-locked bulk lasers there are very few demonstrations of femtosecond oscillators with SFD properties [1-3].