| In this thesis,we investigate a synchronously pumped optical parametric oscillators(SPOPOs)based on intra-cavity pulse compression mechanism.In a signal-oscillated SPOPO,when the signal pulse travels through the nonlinear crystal,the leading edge of signal wave will deplete the peak power of pump,which means that the signal-components at the leading edge will be amplified and those at the tailing edge cannot be,therefore,the signal pulse compression takes place;during the compression process,the signal pulse will generate additional nonlinear acceleration by positive cavity-length detuning corresponding to synchronizing with the pump pulse;the compressed signal pulse is obtained.We have conducted both numerical and experimental investigations of the output characteristics of the compressed pulse in SPOPO under the influence of different parameters.The main research results are summarized as follows:(1)The compression pulse generation process of a synchronous-pumped optical parametric oscillator was numerically simulated based on the three-wave coupling equation.It shows that,when the positive cavity-length detuning was adjusted to the maximum length of the cavity,the compressed signal was soliton-like pulse.Also,the influence of various parameters on the pulse compression mechanism was analyzed,including cavity-length detuning,pump power,output coupling,cavity dispersion,polarization period,and crystal length.(2)A SPOPO based on MgO: PPLN crystal has been designed and built.We found that polarization period of 31.0?m and 2mm-long fused quartz for dispersion compensation could support the shortest pulse output.The soliton-like signal pulse with a duration of 42 fs and an instantaneous bandwidth of 24.4THz(at-20 d B of peak)was obtained,and the timebandwidth product was 0.32.The spectrum of idler pulse with an instantaneous bandwidth of 22.9 THz(at-20 d B of peak)was obtained;after increasing the pump power,the signal pulse with a duration of 50 fs was obtained. |
PDF Full Text Request