Fig. 2
From: Breathing dissipative solitons in optical microresonators
Experimental observation of breathing solitons in Si3N4 and MgF2 platforms. a A similar experimental set-up is used for both platforms: A tunable continuous wave laser is used as a pump source. EDFA, erbium-doped fibre amplifier; EOM, electro-optical phase modulator; OSA, optical spectrum analyser; PD, photodiode; OSC, oscilloscope; ESA, electronic spectrum analyser; VNA, vector network analyser. b Experimental optical spectra of a stationary (blue) and breathing soliton states (red), in the 14 GHz FSR MgF2 crystalline resonator. The effective detuning δ is varied by 0.5 MHz between the two states. The simulated optical spectrum averaged over one breathing period (black line) was offset by 3 dB for better visibility. The arrows mark the positions of weak sidebands visible in both the simulated and measured spectra. c Generated light power evolution for a single-soliton state in the 100 GHz Si3N4 microresonator as the pump is tuned backward, showing the transition from stationary state (green shading) to breathing (red shading) and final decay. The inset shows an SEM image of the microresonator used (the scale bar corresponds to 100 μm). d In the MgF2 crystalline resonator (see inset, the scale bar corresponds to 2 mm), the comb light evolution features a similar behaviour as in d, when tuning backward. The inset shows the oscillations of the generated comb power, resolved with a fast photodiode and high sampling rate. e, f RF spectra of the generated light for a breathing (point (i) in c, d, red trace) and stationary (point (ii) in c, d, blue trace) soliton state respectively in the Si3N4 and MgF2 resonators. In f, the 0.4 GHz span is centred at 0.8 GHz, close to the fundamental breathing frequency. The resolution bandwidth (RBW) is indicated on the corresponding panel. g, h Repetition rate beatnote for a breathing (i, red) and stationary (ii, blue) soliton state in the Si3N4 and MgF2 resonators
