of fabrication from surface generation to coating and the ability to measure these surfaces.
Today, CNC grinding and polishing allow dynamically adjustable cutting paths for tool wear and can be programmed for edging, beveling, sagging, concave, and convex surface grinds. Polymer molding has also become common in fabrication of lenses for consumer and commercial products. Mobile phones, DVD players, digital cameras, and conferencing systems have all incorporated polymer lenses. Glass-molding technology also has become increasingly available in the last decade, as has magnetorheological finishing (MRF) in the fabrication of optical components. In MRF, ferrous-laden fluid passes through an electromagnetic field, where its viscosity is increased, allowing the creation of a precise and repeatable polishing tool. Single-point diamond turning (SPDT) has also grown in popularity in fabricating optical components. It is now routinely used to produce mold inserts for polymer lenses, mold inserts for glass molding, and finished optical elements. The machining process uses single-crystal diamond cutting tools and nanometer-precision positioning to generate spherical surface geometries and more complex geometries, such as toroids, aspheres, and diffractives.
Optical thin-film coatings technology has advanced in response to requirements in diverse markets, including telecommunications, health and medicine, biometrics, and defense. Evaporation deposition processes, in which materials are deposited by way of a transformation from solid to vapor and back to solid, are the most widely used in the optics industry in spite of problems stemming from the porosity of coatings and their sensitivity to humidity and thermal conditions. Metrology is an important enabling technology in the optics industry. There is an old saying, “If you can’t measure it, you can’t make it;” over the last decade, advances in interferometry have improved the ability to measure increasingly challenging optics, particularly aspheres.53,54,55
This section discusses photonics-enabled advances in process technologies with potentially broad applications in numerous manufacturing industries. As noted below, many of these process-technology innovations hold considerable potential
53 PalDey, S., and S.C. Deevi. 2003. Single layer and multilayer wear resistant coatings of (Ti,Al)N: A review. Materials Science and Engineering A 342(1-2):58-79.
54 Kelly, P.J., and R.D. Arnell. 2000. Magnetron sputtering: A review of recent developments and applications. Vacuum 56:159-172.
55 Svedberg, E.B., J. Birch, I. Ivanov, E.P. Munger, and J.E. Sundgren. 1998. Asymmetric interface broadening in epitaxial Mo/W (001) superlattices grown by magnetron sputtering. Journal of Vacuum Science and Technology A: Vacuum, Surfaces, and Films 16(2):633-638.