Theoretical analysis on beam propagation factor of a high-power laser diode

Based on the theory of high order moments of laser beams, the beam propagation factor of a high-power laser diode is analyzed. Analytical expressions are derived for components of the beam factor along the fast (Mx) and slow (My) axis of the junction plane, respectively. It is shown that components of the beam factor Mx and My along orthogonal directions of junction planes of a diode laser may behave in different manners. On one hand, Mx is verified to be four and independent of parameters with regard to waveguide structures. On the other hand, My varies and depends on the ratio of the waveguide parameters. Besides, influences of each structural parameter on behaviors of My and the total one M are also discussed, respectively.