Intersystem crossing effect on photobleaching of Cr^+4 :YAGsaturable absorber as a passive Q-switch

Mathematical model is presented in this work and solved numerically by Rung- Kutta–Fehelberg to study the effect of molecules intersystem crossing ( K isc ) on photobleaching (bleaching time) of Cr :YAG ^+4 crystal as a saturable absorber material (passive Q- switch ) with 4 Nd :GdVO laser. The study show the increasing of molecules intersystem crossing into energy levels decreasing the bleaching time of saturable absorber material to lead fast built-up laser pulse.