Compression moulding of precision diffractive glass

Microlens and diffractive optical lenses and mirror are increasingly used in optomechanical devices. However currently these optics are either fabricated using cleanroom technology or direct ultraprecision machining process therefore the cost of manufacturing remains high. The method discussed in this paper is different from traditional fabrications processes, i.e., instead of direct manufacturing, a replication method based on compression glass moulding process is presented. Glass moulding is an affordable high volume production process. Moulded micro and diffractive components have superior geometric tolerance and optical performance as compared to plastic optics. Through design, fabrication and measurement of a low Tg glass DOE using compression moulding technology, the authors' research in glass moulding has shown that diffractive optical components can be manufactured in large quantity with tolerances meet or exceed requirements for precision optics. It has been demonstrated that compression moulding can be a promising process for high volume production of precision DOEs with micro and nano scale features. Geometrical and optical characterizations of the moulded DOEs were demonstrated using different measurement techniques.