Strain relaxation in strained buried heterostructure lasers

Calculations of the stress/strain distribution in a buried strained heterostructure laser are performed for active regions with aspect ratios ranging from 1:1 to 40:1 and an overall misfit strain of 1%. The strain relaxation is found to be small for the high aspect ratios over the central 75% of the active region. Considerable relaxation of the strain occurs at the edges of the active region, however, and throughout the whole cross section for the smaller aspect ratios. The maximum shear stress is found to occur at the corners of the strained region in agreement with previous calculations.