On the base of the theory of rate equation assuming the intracavity photon density Gaussian approximation,the theoretical and experimental studies on pulse energy,peak power and pulse width in a LD end pumped Cr4+:YAG passively Q-switched Nd:YVO4laser have been presented to get all solid state high repetition Q-switched laser with optimal output characteristics.According to the rate equation assuming the plane wave approximation, this thesis has given the numerical solution of rate equation considering the intracavity photon intensity Gauss spatial distribution after defining the normalized parameters.Using composite simpson rule expansion and runge-kutta method,we have got the relationships between normalized intracavity photon density0(0,r) and normalized time τ, normalized intracavity photon count Φint and N, ωL/ωP where ωL is the radius of laser,ωp is the average radius of the pump beam.we also got the relationships between the maximum of Φ(O,τ) and τ,N,ωL/ωP.On the basis of rate equation assuming Gaussian wave approximation,we have optimized the output characteristics on LD end pumped Cr4+:YAG passively Q-switched Nd:YVO4laser and got the parameters lines simulated between output characters and cavity resonator.Establish LD end pumped Cr4+:YAG passively Q-switched Nd:YVO4laser experimental platform,study the laser pulse energy,peak power and pulse width.The result proves that the pulse energy or peak power or pulse width are in agreement with the optimal results using Ropt and TOopt approached. |