Difference Frequency Comb DFC

The DFC locking electronics consisting of the Phase Frequency Detector (PFD) and FALC 110 provides high-end phase frequency locking for comb applications. The PFD RF input is designed for use with the RF output signal of the DFC MD. The error signal generated by the PFD is fed to the input of the FALC 110 regulator. The main output of the FALC is passed through the PFD to allow for remote switching of the fast feedback loop which modulates the laser diode current. A copy of the error signal (mon. out) is used to close the slow feedback loop acting on the DL pro piezo (Fine In) with the all-digital PID of the DLC pro. Slow and fast feedback loop can be enabled and disabled with a push of a button in the DFC user interface (TOPAS DFC).