Fig. 1. Principle of low phase noise microwave signal generation based on soliton frequency comb in MgF₂ microresonator

Fig. 2. Spectral evolution of optical frequency comb and soliton generation conditions and stabilization mechanism in MgF₂ microresonator. (a) Spectral evolution; (b) generation conditions of soliton; (c) bistable mechanism of soliton

Fig. 3. Time and radio frequency (RF) domain evolutions corresponding to spectral evolution of MgF₂ microresonator. (a) Time domain evolution; (b) RF frequency domain evolution

Fig. 4. Experimental scheme of low phase noise microwave signal generation based on soliton optical frequency comb in MgF₂ microresonator

Fig. 5. Morphology and Q value of MgF₂ microresonator. (a) MgF₂ microresonator morphology; (b) ring-down waveform and Q measurement

Fig. 6. Soliton steps, sweep parameters, and soliton comb of MgF₂ microresonator. (a) Soliton steps; (b) sweep speed and sweep range of pump laser; (c) measured results of soliton comb in 100 nm and 10 nm ranges

Fig. 7. Evolution in RF frequency domain

Fig. 8. RF spectrum and phase noise of 15.38 GHz microwave signal. (a) RF spectrum; (b) phase noise