We review, with proper derivation and proofs, the common undergraduate formulas for building images of objects using a system of lenses with spherical surfaces. This is done using the first-order approximation which a...We review, with proper derivation and proofs, the common undergraduate formulas for building images of objects using a system of lenses with spherical surfaces. This is done using the first-order approximation which assumes that light rays deviate from the symmetry axis by only small angles. Yet, even this most basic approximation results in surprisingly complex theory, which is then applied to explain workings of everyday optical instruments.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
文摘We review, with proper derivation and proofs, the common undergraduate formulas for building images of objects using a system of lenses with spherical surfaces. This is done using the first-order approximation which assumes that light rays deviate from the symmetry axis by only small angles. Yet, even this most basic approximation results in surprisingly complex theory, which is then applied to explain workings of everyday optical instruments.
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.
