Investigation of the Mode Structures of Multiphoton Induced Ultraviolet Laser in a ZnO Microrod

Hexagonal wurtzite structural zno microrods were fabricated by vapor-phase transport method. under the excitation of a pulse laser with 1200 nm wavelength,the multiphoton induced ultraviolet (uv) laser was observed in a microrod. the dependence of the laser mode structures on pump intensity was investigated. the result indicates that the laser belongs to whispering gallery mode (wgm) at low pump intensity and fabry-perot (fp) mode at high pump intensity. the corresponding positive feedback mechanisms were discussed. © 2017 guangping zhu.