BEAM INSTABILITY IN 980-NM POWER LASERS - EXPERIMENT AND ANALYSIS

A theoretical analysis of beam instability (steering), commonly observ ed in high power ridge waveguide laser diodes is presented, A physical model of multiple interfering lateral modes is proposed and implement ed in a two-dimensional self-consistent numerical code, It is shown th at the dynamic evolution of the effective waveguide and the coherent l asing of emergent multiple lateral modes of the waveguide under high i njection could lead to beam steering and knees in the fiber coupled L- l characteristics. The theory of simultaneous lasing and interaction b etween several lateral modes is found to be consistent with the observ ed back-plane radiation image.