layer 1 directly contributed along with the forces of the micro machining creation process to the degree of curvature of the mirror slab the thicker the gold layer the greater the concave curvature as shown by the arrow in that figure such concave curvature force was measured at a thickness on the order of 5000 u00e5 thus referring now to fig3 a profilometer inter ferogram for the prior art mirror shown in fig1 is shown in this case with a gold reflective coating of 5000 u00e5 the mirror surface is concave with a radius of curvature equal to u2212 11 77 mm correspondingly referring now to fig4 a profilometer inter ferogram for the mirror construction of the present invention is shown here the enhanced bending resistant structure allows an increase of the radius of curvature of the mirror to u2212 16 12 mm interestingly it was also found that thin layers of the reflective coating of gold caused an opposite convex curvature of the mirror with the enhanced structure such convex curvature force was measured at a thickness on the order of u2245 500 u00e5 thus referring to fig5 the surface profile of a mirror of 500 u00e5 thickness is shown having a radius.