We changed the fiber to the wavemeter. The third fiber worked best and we could operate the WM at low exposure times, i.e., below the laser repetition rate. We used the neutral density filter to adapt the laser power that only one laser pulse is measured by the WM each time (Exposure time =34ms)

This way, there are no frequency jumps. The jitter is slighly different at each wavelength which was ~5GHz peak to peak.


We optimized the fiber coupler and slightly optimized the jitter to <4GHz.