The thermal stability of a vertical-cavity surface-emitting laser (VCSEL) array is enhanced by redesigning the mesa arrangement.Based on a thermoelectric coupling three-dimensional (3D) finite-element model,an optimized VCSEL array is designed.The effects of this optimization are studied experimentally.Power density characteristics of VCSEL arrays with different mesa configuration are obtained under different thermal stress in which the optimized device shows improved performance.Optimized device also shows better stability from measured spectra and calculated thermal resistances.The experimental results prove that our simulation model and optimization is instructive for VCSEL array design.