Self-frequency-doubling Yb:CNGS lasers operating in the femtosecond regime

We study Yb:Ca3NbGa3Si2O14 (Yb:CNGS) lasers in the mode-locked regime, focusing on their self-frequency-doubling potential. We characterize the laser performance in configurations without and with phase-matching for second-harmonic generation. In the former case, the laser generates 47 fs pulses at a central wavelength of 1052 nm with an average output power of 45 mW at 78.4 MHz. These pulses are further compressed extracavity down to 40 fs, which indicates that the employed crystal is one of the most promising novel gain media regarding ultrafast laser operation. Furthermore, we demonstrate that in a configuration close to phase-matching, the laser emits 40 mW of fundamental radiation at 1046 nm with 100 fs pulse duration simultaneously producing 66 mW of second-harmonic centered at 525 nm. In order to better describe the self-frequency-doubling phenomenon, we compare our experimental observations obtained in both configurations with results of numerical modeling.