Fig. 1. Experimental setup for CW single-frequency infrared laser generated by a SRO

Fig. 2. Diagram of PPLN crystal

Fig. 3. Output power of signal and idler versus pump power

Fig. 4. Profile of the signal

Fig. 5. Signal and idler wavelength versus PPLN crystal temperature at different polarization periods

Fig. 6. Signal and idler powers versus temperature of PPLN crystal

Fig. 7. Transmitted intensity of F-P interferometer

Fig. 8. Output power of the signal and idler versustime when the SRO was free running

Fig. 9. Frequency drift of the signal when the SRO free running