Hu Qiquan

Propagation properties of off-axis Hermite-cosh-Gaussian beam combinations through a first-order optical system

Based on the Collins integral formula, the analytic expressions of propagation of the coherent and the incoherent off-axis Hermite?cosh?Gaussian (HChG) beam combinations with rectangular symmetry passing through a paraxial first-order optical system are derived, and corresponding numerical examples are given and analysed. The resulting beam quality is discussed in terms of power in the bucket (PIB). The study suggests that the resulting beam cannot keep the initial intensity shape during the propagation and the beam quality for coherent mode is not always better than that for incoherent mode. Reviewing the numerical simulations of Gaussian, Hermite?Gaussian (HG) and cosh?Gaussian (ChG) beam combinations indicates that the Hermite polynomial exerts a chief influence on the irradiance profile of composite beam and far field power concentration.

Light‐induced drift in a discharge tube

Recently the light‐induced drift (LID) effect has been studied theoretically and experimentally /1–6/. The evolution equations of this effect are nonlinear and with a soliton‐type solution. The LID effect in discharge condition will allow using more kinds of atoms (using sputtering effect, for example) and more atomic states (metastable state) so that some possible new applications may be found. When we deal with LID in a discharge tube, we have to consider a multi‐level system instead of two‐level system as the non‐discharge case does and have to consider the Langmuir mobile effect.