Fig. 2: Experimental setup and example measurements.
From: Coherent suppression of backscattering in optical microresonators
a Optical circuitry, consisting of a fibre-coupled external cavity diode laser (1.55 µm) amplified by an erbium-doped fibre amplifier (EDFA), a polarisation controller (PC) to optimise the coupling to the desired resonator mode, a circulator to separate the propagation directions in the fibre, and photodetectors to monitor the backscattering (PD1) and transmission of the microresonator (PD2). The tungsten tip near-field probe was fixed to a piezo positioner. Example backscattering b and transmission c spectra with fitted Lorentzians (black) for one position of the near-field probe, showing the transmission linewidth 2γ
