Diamond milling is a key process in the fabrication of custom micro optics and in fabricating the injection molds used in the plastic injection molding of micro optics.  Diamond milling is very similar to conventional milling with CNC mills with one huge difference.  Whereas conventional CNC milling creates shapes that are fairly large, diamond milling is capable of creating structres down to 1 micron in size.  Not only is diamond milling capable of creating micro structures, but these structures can also take a wide variety of shapes.  The shapes can be binary, blazed gratings, Fresnel zones, free forms, and basically any other shapes you can think of. 

One of the biggest strengths of the process is relatively low tooling costs.  A normal bit for diamond milling costs about $3,000.  Custom diamond milling bits cost about $6,000 to $8,000.  However, outside of the cost for the bit the only other charge for diamond milling is the time it takes to machine the optic.  The machining time for diamond milling is very much dependent on the surface roughness needed, the depth of the structures, and the material being milled. 

Diamond milling can also be used on many different materials.  Some of the easier materials to machine  are glasses and plastics.   Glasses are fairly hard materials but not anywhere near as hard as metals.  Plastics are soft but can actually be so soft that they are difficult to machine because the diamond milling bit must go slow so that it doesn't create enough heat to actually melt the surface layer of the plastic.  Diamond milling of metals is usually the most difficult and metals used are stainless steel and copper/beryllium alloy for injection molds as well as other metals such as gold for mirror surfaces. 

Nalux is well equipped for the diamond milling process and has the technical staff capable of using these tools to make the optics you need.  Give us a call and find out about our solutions.