Figure 3: Experimental setup.
From: Spiral resonators for on-chip laser frequency stabilization
Two, fibre lasers independently locked to high-Q spiral reference cavities using Pound–Drever–Hall (PDH) locking systems. Each PDH locking loop includes a photodiode (PD), electro-optic modulator (EOM), local oscillator (LO) and proportional-integral-differential feedback controller (PID). The outputs of the separately locked lasers were combined on a photodetector and the resulting photocurrent was analysed using an electrical spectrum analyser (ESA), a frequency counter and a phase-noise analyser. All components are on the same optical table.
