INVESTIGATION ON THE PUMP ACCEPTANCE BANDWIDTH FOR COLLINEAR QUASI-PHASE-MATCHING OPTICAL PARAMETRIC AMPLIFICATION

We investigated the issue of parametric bandwidth for a collinear quasi-phase-matching (QPM) optical parametric amplification (OPA). Mathematical model for evaluating the parametric bandwidth tolerance of the OPA was derived by expanding the wave-vector mismatch in Taylor series and taking the first two terms into consideration for accuracy. Based on the model, the variation of pump acceptance spectral bandwidth with parametric wavelength was discussed. The correlating curve of the pump wavelength and the parametric wavelength was obtained for the largest pump acceptance spectral bandwidth. These results were compared to that obtained by numerically calculating the parametric gain curves of OPA when pumped with different Gauss bandwidths by means of three-wave mixing equations directly, and were found to be in good accordance. The results presented are helpful for specifying the optimal pump wavelength of the parametric amplification and oscillation.