Fig. 5.

A) Pulse width measurements of the ultrafast SDL in combination with the 20x microscope objective. B) The SDL has a spectrum with 9.5 nm full width at half maximum (FWHM) (i.e the spectrum is supporting 118 fs pulses). C-D) Fundamental mode-locking is demonstrated with the Radio Frequency (RF) traces taken at the main laser frequency of 1.63 GHz and on its harmonics. The drop of the power in the harmonics is due to the limited bandwidth of the RF amplifier used to measure it. The resolution bandwidth (RBW) is the smallest frequency increment that can be resolved.