Spatial chirp and angular dispersion of the nonlinear crystal for a femtosecond OPO

In this paper spatial chirp and angular dispersion are calculated theoretically and analyzed for a four-mirror, standing-wave cavity femtosecond OPO. The analytical expression of spatial chirp in the nonlinear crystal is deduced. The analytical expressions of second- and third-order dispersion including angular dispersion of the nonlinear crystal are presented, for the noncollinear type-I phase-matched Fs BBO OPO using angle tuning. Moreover, variations of GDD and TOD with cavity parameters are calculated exactly. The analysis method and the obtained result also are efficacious for a same type Fs OPO.