Fig. 1. Experimental setup of OPO synchronously pumped by Yb∶LYSO laser

Fig. 2. Signal tuning characteristics of OPO synchronously pumped by Yb∶LYSO laser. (a) Spectrum; (b) output power

Fig. 3. Output performances of OPO with intra-cavity frequency-doubling. (a) Tuning characteristic of SHG; (b) beam quality at maximum output power

Fig. 4. Experimental setup of femtosecond KTA-OPO

Fig. 5. KTA-OPO. (a) Spectra of tunable signals; (b) spectra of idlers

Fig. 6. Experimental setup of femtosecond BIBO-OPO synchronously pumped by femtosecond green light. (a) Signal output; (b) idler output

Fig. 7. Output performances of tunable signals of BIBO-OPO. (a) Spectra and power; (b) corresponding pulse durations before and after compression

Fig. 8. Output performances of tunable idlers of BIBO-OPO. (a) Spectra and power; (b) corresponding pulse durations

Fig. 9. Experimental setup of BIBO-OPO with repetition rate of 755 MHz

Fig. 10. Output performances of BIBO-OPO with repetition rate of 755 MHz. (a) Tuning curves of signals; (b) phase noise

Fig. 11. Experimental setup of gigahertz femtosecond OPO based on Vernier harmonically pumping

Fig. 12. OPO output. (a) Spectra of signals of femtosecond OPOs at different repetition rates; (b) ΔL and average output power versus repetition rate; (c) spectrum when OPO operates at repetition rate of 37.3 GHz