For a surface to be optically smooth, any features or irregularities on it must be significantly smaller than the wavelength of light incident on that surface. Optec excimer laser systems have recently demonstrated the capability to produce optically smooth fibre coupling lenses from polymethyl methacrylate (PMMA).
PMMA can be machined smoothly using 193 nm lasers, and the depth of material removed is proportional to the accumulated shot dose. Non-re-entrant shapes, such as lenses, can be produced by Contour Sectioning (CS), whereby the shape is divided into vertical slices corresponding to the depth of material removed with a single shot. Then by removing the smallest slices first, an optically smooth feature can be produced. Using an array of motifs on a mask plate corresponding to the slices and a laser source large enough to illuminate them all, a machinist can produce an arbitrarily long array of finished motifs in a single operation.
To find out more about how Optec excimer technology can aid in your business, contact Raymax on (02) 9979 7646 or using the contact form below.
