Fig. 1. Epitaxial structures of used gain chip and SBR in experiment. (a) Gain chip; (b) SBR

Fig. 2. Schematic of resonant cavity of SBR passively mode-locked VECSEL with 67 MHz repetition rate

Fig. 3. Pulses with different waveforms observed in experiment. (a) Stable CW mode-locked pulse; (b) unstable double-pulse; (c) unstable triple-pulse

Fig. 4. Numerical simulation of pulse formation in passively mode-locked VECSEL. (a) Pulse under CW mode-locking; (b) coupled double-pulse when saturation fluence of saturable absorber is higher; (c) multi-pulse when saturation fluence of saturable absorber is lower

Fig. 5. Fundamental and high-order harmonic mode-locked waveforms observed in experiment. (a) Temporal waveform of stable fundamental CW mode-locked pulse; (b) temporal waveform of stable second-harmonic mode-locked pulse; (c) temporal waveform of fourth-harmonic mode-locked pulse with amplitude modulation; (d) temporal waveform of sixth-harmonic mode-locked pulse with amplitude modulation; (e) temporal waveform of eighth-harmonic mode-locked pulse with amplitude modulation; (f) temporal waveform of pulse with harmonic order higher than eight

Fig. 6. Measured experimental results of fundamental CW mode-locking. (a) Temporal waveform of fundamental CW mode-locked pulse; (b) temporal waveform of fundamental CW mode-locked pulse in longer time span; (c) radio frequency spectrum of fundamental CW mode-locked pulse; (d) higher order harmonic signal of pulse; (e) autocorrelation measurement result of pulse width ; (f) spectrum of mode-locked laser

Fig. 7. Output power versus absorbed pump power of SBR passively mode-locked VECSEL