angles of divergence either in a random or non random manner for a uniform fill of diffuse radiation patterns 38 fig1 additionally or alternatively the microlenses have different respective optical powers after microlens array 21 has been formed in an epitaxial semiconductor layer as described above anode contacts 26 are formed above the microlens array in the positions prepared for in the patterning stage described in the context of fig2 b and the full vcsel manufacturing process is completed resulting in vcsel array 20 fig1 in the alternative case wherein microlens array 21 is formed in a dielectric material the deposition of transparent crystalline layer 40 and the forming of microlens array 21 take place after completion of the vcsel manufacturing process except for subsequent wafer thinning and backside cathode deposition as previously described fig1 openings are patterned and etched in microlens array 21 for gaining access to anodes 26 which have been buried under transparent crystalline layer 40 in the process fig3 a b are schematic illustrations of the successive stages of manufacture of a randomly rough diffusing surface on top of vcsel epitaxy layers 24 in accordance with another embodiment of the invention fig3 a is a schematic illustration showing a transparent crystalline layer 50 deposited over vcsel epitaxy layers 24 transparent crystalline layer 50 is a planar layer which will become a diffuser in the next stage it may have different material properties from transparent crystalline layer 40 of fig2 a due to the process requirements of the disclosed embodiment materials with local non uniformities due to either material composition or crystal grain structure are advantageous in creating the non uniform etch in the process step illustrated in fig3 b fig3.