Direct integration of aspherical microlens on vertical-cavity surface emitting laser emitting surface for beam shaping

The aspherical microlens used for beam shaping of vertical-cavity surface emitting lasers (VCSELs) was designed and fabricated. The microlens designed as needed was directly fabricated and integrated in one step on the emitting surface of a VCSEL by femtosecond laser direct writing (FsLDW). By the microlens’ shaping the beam quality of VCSELs can be remarkably improved, especially the reduction of the divergence angle. The experiment results agree with the numerical modeling results. After integrating aspherical microlenses the far-field divergence angle of the VCSEL was reduced from 18.16° to 0.83°. This novel technique has great potential in the field of miniature and low power integrated optical system.