Fig. 1. Experimental setup of high-power green femtosecond laser system

Fig. 2. Evolution of spectra and output power curves of main amplifiers. (a) Evolutions of spectra at various amplifier stages; (b) output power curves of two rod-type fiber amplifiers

Fig. 3. Results of coherent beam combining. (a) Output spectra of two channels of main amplifiers and spectrum of combined light; (b) combining efficiency versus output power of combined light; (c) time series of combined light intensity

Fig. 4. Autocorrelation traces of two channels of main amplifiers and combined light

Fig. 5. Beam quality of fundamental light after beam reduction (inset is fundamental light spot at position of LBO crystal)

Fig. 6. Results of high-power second-harmonic generation. (a) Green light power and conversion efficiency versus fundamental power; (b) beam quality of 128 W green light (inset is near-field spot of green light)

Fig. 7. Spectral and time domain characteristics of high-power green light. (a) Spectrum of green light; (b) autocorrelation curve of green light

Fig. 8. PSD and RIN of output light intensity at each stage