Diffraction efficiency of grating plays an important role in output power of incoherent fiber laser beam combination. Through theoretic analysis and numerical simulations it has been proved that the diffraction effici...Diffraction efficiency of grating plays an important role in output power of incoherent fiber laser beam combination. Through theoretic analysis and numerical simulations it has been proved that the diffraction efficiency would increase with the decrease of grating frequency and wavelength bandwidth. On the condition that the width of a fiber array is fixed at W=I 0 cm, an optimum grating frequency were numerically simulated as f=230 mm^-1. Also an unequal interval method was proposed to improve the system efficiency of diffraction into 0.4293, which is higher than 0.3824 under the equal interval condition.展开更多
In the present work,nonlinear interaction of elliptical laser beam with collisional plasma is studied by using paraxial ray approximation.Nonlinear differential equations for the beam width parameters of semi-major ax...In the present work,nonlinear interaction of elliptical laser beam with collisional plasma is studied by using paraxial ray approximation.Nonlinear differential equations for the beam width parameters of semi-major axis and semi-minor axis of elliptical laser beam have been set up and solved numerically to study the variation of beam width parameters with normalized distance of propagation.Effects of variation in absorption coefficient and plasma density on the beam width parameters are also analyzed.It is observed from the analysis that extent of self-focusing of beam increases with increase/decrease in plasma density/absorption coefficient.展开更多
基金Supported by the National Natural Science Foundation of China(60678018)
文摘Diffraction efficiency of grating plays an important role in output power of incoherent fiber laser beam combination. Through theoretic analysis and numerical simulations it has been proved that the diffraction efficiency would increase with the decrease of grating frequency and wavelength bandwidth. On the condition that the width of a fiber array is fixed at W=I 0 cm, an optimum grating frequency were numerically simulated as f=230 mm^-1. Also an unequal interval method was proposed to improve the system efficiency of diffraction into 0.4293, which is higher than 0.3824 under the equal interval condition.
文摘In the present work,nonlinear interaction of elliptical laser beam with collisional plasma is studied by using paraxial ray approximation.Nonlinear differential equations for the beam width parameters of semi-major axis and semi-minor axis of elliptical laser beam have been set up and solved numerically to study the variation of beam width parameters with normalized distance of propagation.Effects of variation in absorption coefficient and plasma density on the beam width parameters are also analyzed.It is observed from the analysis that extent of self-focusing of beam increases with increase/decrease in plasma density/absorption coefficient.
