Fig. 1. Optical path device and application device. (a)--(d) Each part of optical path device; (e) application device

Fig. 2. Experimental results. (a) Supercontinuum; (b) f₀ signal; (c) linewidth of f₀ when free running and locking (illustration); (d) spectrum broadening

Fig. 3. System device. (a) Feedback control diagram; (b) phase lock circuit; (c) temperature control device

Fig. 4. Frequency drift of f_r and f₀. (a) Frequency drift of f_r with and without water cooling; (b) frequency drift of f₀ with water cooling; (c) relationship between SNR of f₀ and LD current

Fig. 5. Results of feedback control. (a) Frequency drift of f_r with temperature feedback; (b) frequency drift of f₀ with LD current feedback; (c) variation of T_Cu2 and TEC2 temperature; (d) variation of LD current

Fig. 6. Results of f_r and f₀ measurement. (a) Frequency counts; (b) Allan deviation

Fig. 7. Gas absorption spectrum. (a) Absorption spectrum of H₂O; (b) absorption spectrum of ¹²CO; (c) comparison of absorption spectrum of ¹²C₂H₂ with HITRAN database