Analysis on the characteristic of cold complex cavity with gradual transition of various obliquity

Based on the theory of mode-coupling, an analysis on cold complex cavity with gradual transition is presented, in which the multiple modes coupling are taken into account. The influences of the obliquity of taper section coupling on the axial field amplitude profile and the Q value of this complex cavity are analyzed. Theoretical analysis and simulation indicate that choosing suitable obliquity can ensure good amplitude magnification which helps to improve the efficiency of beam-wave interaction.